title: WPF 4.0 Global Style Issue
body: <p>I develop a WPF application (target .Net 4.0).
  I define global style like this</p>
  
  <pre><code>&lt;Application.Resources&gt;
      &lt;ResourceDictionary&gt;
          &lt;ResourceDictionary.MergedDictionaries&gt;
              &lt;ResourceDictionary Source="pack://application:,,,/BuildingInspector;component/Resources/Languages/fr-FR.xaml" /&gt;
              &lt;!--&lt;ResourceDictionary Source="pack://application:,,,/BuildingInspector;component/Resources/ButtonStyles.xaml" /&gt;--&gt;
          &lt;/ResourceDictionary.MergedDictionaries&gt;
  
          &lt;ControlTemplate x:Key="ctButton" TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Grid&gt;
                  &lt;Border&gt;
                      &lt;Border.Style&gt;
                          &lt;Style TargetType="Border"&gt;
                              &lt;Setter Property="BorderThickness" Value="0" /&gt;
                              &lt;Setter Property="Background" Value="Transparent" /&gt;
                          &lt;/Style&gt;
                      &lt;/Border.Style&gt;
                  &lt;/Border&gt;
                  &lt;ContentPresenter Content="{Binding Path=(app:DependencyProperties.ImagePath), RelativeSource={RelativeSource AncestorType={x:Type telerik:RadButton}}}" /&gt;
              &lt;/Grid&gt;
          &lt;/ControlTemplate&gt;
  
          &lt;!-- Style par défault des boutons --&gt;
          &lt;Style x:Key="defaultButtonStyle" TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="Template" Value="{DynamicResource ctButton}" /&gt;
          &lt;/Style&gt;
  
          &lt;!-- Style du bouton "Add" --&gt;
          &lt;Style x:Key="addButtonStyle" 
                 BasedOn="{StaticResource ResourceKey=defaultButtonStyle}" 
                 TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="app:DependencyProperties.ImagePath" Value="{DynamicResource ResourceKey=pathAdd}" /&gt;
              &lt;Setter Property="app:DependencyProperties.Color" Value="LightGreen" /&gt;
              &lt;Setter Property="app:DependencyProperties.MouseOverColor" Value="GreenYellow" /&gt;
              &lt;Setter Property="app:DependencyProperties.PressedColor" Value="Green" /&gt;
          &lt;/Style&gt;
  
          &lt;!-- Style du bouton "Cancel" --&gt;
          &lt;Style x:Key="cancelButtonStyle" 
                 BasedOn="{StaticResource ResourceKey=defaultButtonStyle}" 
                 TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="app:DependencyProperties.ImagePath" Value="{DynamicResource ResourceKey=pathCancel}" /&gt;
              &lt;Setter Property="app:DependencyProperties.Color" Value="Salmon" /&gt;
              &lt;Setter Property="app:DependencyProperties.MouseOverColor" Value="SandyBrown" /&gt;
              &lt;Setter Property="app:DependencyProperties.PressedColor" Value="Red" /&gt;
          &lt;/Style&gt;
  
          &lt;!-- Style du bouton "Delete" --&gt;
          &lt;Style x:Key="deleteButtonStyle" 
                 BasedOn="{StaticResource ResourceKey=defaultButtonStyle}" 
                 TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="app:DependencyProperties.ImagePath" Value="{DynamicResource ResourceKey=pathDelete}" /&gt;
              &lt;Setter Property="app:DependencyProperties.Color" Value="Salmon" /&gt;
              &lt;Setter Property="app:DependencyProperties.MouseOverColor" Value="SandyBrown" /&gt;
              &lt;Setter Property="app:DependencyProperties.PressedColor" Value="Red" /&gt;
          &lt;/Style&gt;
  
          &lt;!-- Style du bouton "Exit" --&gt;
          &lt;Style x:Key="exitButtonStyle" 
                 BasedOn="{StaticResource ResourceKey=defaultButtonStyle}" 
                 TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="app:DependencyProperties.ImagePath" Value="{DynamicResource ResourceKey=pathExit}" /&gt;
              &lt;Setter Property="app:DependencyProperties.Color" Value="Salmon" /&gt;
              &lt;Setter Property="app:DependencyProperties.MouseOverColor" Value="SandyBrown" /&gt;
              &lt;Setter Property="app:DependencyProperties.PressedColor" Value="Red" /&gt;
          &lt;/Style&gt;
  
          &lt;!-- Style du bouton "Next" --&gt;
          &lt;Style x:Key="nextButtonStyle" 
                 BasedOn="{StaticResource ResourceKey=defaultButtonStyle}" 
                 TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="app:DependencyProperties.ImagePath" Value="{DynamicResource ResourceKey=pathNext}" /&gt;
              &lt;Setter Property="app:DependencyProperties.Color" Value="LightGreen" /&gt;
              &lt;Setter Property="app:DependencyProperties.MouseOverColor" Value="GreenYellow" /&gt;
              &lt;Setter Property="app:DependencyProperties.PressedColor" Value="Green" /&gt;
          &lt;/Style&gt;
  
          &lt;!-- Style du bouton "Save" --&gt;
          &lt;Style x:Key="saveButtonStyle" 
                 BasedOn="{StaticResource ResourceKey=defaultButtonStyle}" 
                 TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="app:DependencyProperties.ImagePath" Value="{DynamicResource ResourceKey=pathSave}" /&gt;
              &lt;Setter Property="app:DependencyProperties.Color" Value="LightGreen" /&gt;
              &lt;Setter Property="app:DependencyProperties.MouseOverColor" Value="GreenYellow" /&gt;
              &lt;Setter Property="app:DependencyProperties.PressedColor" Value="Green" /&gt;
          &lt;/Style&gt;
  
  
          &lt;!-- Style du Path (contenu) des boutons --&gt;
          &lt;Style x:Key="pathButtonStyle" TargetType="Path"&gt;
              &lt;Setter Property="Fill"
                      Value="{Binding Path=(app:DependencyProperties.Color), RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=telerik:RadButton}}"/&gt;
              &lt;Style.Triggers&gt;
                  &lt;DataTrigger Binding="{Binding Path=IsMouseOver, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=telerik:RadButton}}"
                               Value="True"&gt;
                      &lt;Setter Property="Fill" 
                              Value="{Binding Path=(app:DependencyProperties.MouseOverColor), RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=telerik:RadButton}}"/&gt;
                  &lt;/DataTrigger&gt;
                  &lt;DataTrigger Binding="{Binding Path=IsPressed, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=telerik:RadButton}}"
                               Value="True"&gt;
                      &lt;Setter Property="Fill"
                              Value="{Binding Path=(app:DependencyProperties.PressedColor), RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=telerik:RadButton}}"/&gt;
                  &lt;/DataTrigger&gt;
                  &lt;DataTrigger Binding="{Binding Path=IsEnabled, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=telerik:RadButton}}"
                               Value="False"&gt;
                      &lt;Setter Property="Fill"
                              Value="{Binding Path=(app:DependencyProperties.DisabledColor), RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=telerik:RadButton}}"/&gt;
                  &lt;/DataTrigger&gt;
              &lt;/Style.Triggers&gt;
          &lt;/Style&gt;
  
  
          &lt;!-- Contenu du bouton "Add" --&gt;
          &lt;Grid x:Key="pathAdd"&gt;
              &lt;Grid Name="addBackgroundGrid" MinWidth="48" MinHeight="48" Visibility="Collapsed" /&gt;
              &lt;Path Data="M2.880352,35.504997L25.563028,35.504997 25.461889,35.77055C24.680614,37.90033 24.254,40.199783 24.254,42.596951 24.254,44.994007 24.680614,47.293259 25.461889,49.422794L25.562908,49.688 2.880352,49.688C1.290522,49.688,3.8410201E-07,48.396416,0,46.807915L0,38.38258C3.8410201E-07,36.794079,1.290522,35.504997,2.880352,35.504997z M41.691601,32.867001L41.691601,40.591217 33.968002,40.591217 33.968002,45.48729 41.691601,45.48729 41.691601,53.211002 46.587406,53.211002 46.587406,45.48729 54.311005,45.48729 54.311005,40.591217 46.587406,40.591217 46.587406,32.867001z M44.126499,27.625C52.394669,27.625 59.098,34.325611 59.098,42.596501 59.098,50.859093 52.394669,57.565003 44.126499,57.565003 35.858036,57.565003 29.156,50.859093 29.156,42.596501 29.156,34.325611 35.858036,27.625 44.126499,27.625z M2.880352,17.594002L43.182121,17.594002C44.771912,17.594002,46.061001,18.882946,46.061001,20.471779L46.061001,22.816408 45.653107,22.780068C45.149128,22.741593 44.639954,22.722 44.126297,22.722 37.278214,22.722 31.227619,26.205 27.652683,31.492657L27.472803,31.773003 2.880352,31.773003C1.290522,31.773001,3.8410201E-07,30.484057,8.8062882E-07,28.893322L8.8062882E-07,20.471779C3.8410201E-07,18.882946,1.290522,17.594002,2.880352,17.594002z M8.4794798,3.8200022C6.678607,3.8200022 5.2110004,5.2864023 5.2110014,7.0887662 5.2110004,8.8935586 6.678607,10.357 8.4794798,10.357 10.281624,10.357 11.748,8.8935586 11.748,7.0887662 11.748,5.2864023 10.281624,3.8200022 8.4794798,3.8200022z M2.880352,0L43.182117,0C44.771912,5.590332E-07,46.061001,1.2890898,46.061001,2.8779911L46.061001,11.302441C46.061001,12.893875,44.771912,14.18,43.182117,14.18L2.880352,14.18C1.290522,14.18,3.8410201E-07,12.893875,0,11.302441L0,2.8779911C3.8410201E-07,1.2890898,1.290522,5.590332E-07,2.880352,0z" 
                    Stretch="Uniform" Width="26" Height="26" Margin="0,0,0,0" RenderTransformOrigin="0.5,0.5"
                    Style="{DynamicResource ResourceKey=pathButtonStyle}"&gt;
                  &lt;Path.RenderTransform&gt;
                      &lt;TransformGroup&gt;
                          &lt;TransformGroup.Children&gt;
                              &lt;RotateTransform Angle="0" /&gt;
                              &lt;ScaleTransform ScaleX="1" ScaleY="1" /&gt;
                          &lt;/TransformGroup.Children&gt;
                      &lt;/TransformGroup&gt;
                  &lt;/Path.RenderTransform&gt;
              &lt;/Path&gt;
          &lt;/Grid&gt;
  
          &lt;!-- Contenu du bouton "Cancel" --&gt;
          &lt;Grid x:Key="pathCancel"&gt;
              &lt;Grid Name="cancelBackgroundGrid" Width="48" Height="48" Visibility="Collapsed" /&gt;
              &lt;Path Data="M2.9505676,36.439814L21.343939,36.439814C20.303749,39.110218 19.703638,42.000652 19.703638,45.041111 19.703638,47.101423 19.993691,49.091722 20.493784,50.992008L2.9505676,50.992008C1.3202689,50.992008,2.6905189E-05,49.67181,2.6147463E-05,48.041565L2.6147463E-05,39.400261C2.6905189E-05,37.760014,1.3202689,36.439814,2.9505676,36.439814z M43.691771,27.403506C43.883024,27.398506,44.075529,27.398506,44.270537,27.403506L44.280539,27.403506 44.300539,27.403506C46.750612,27.423509,49.070685,27.943573,51.18075,28.873688L51.25075,28.913692C57.48094,31.684034 61.801073,37.954807 61.73107,45.205702 61.631067,54.946903 53.660826,62.767868 43.920527,62.667858 36.320295,62.587849 29.900101,57.707245 27.500027,50.946411L33.810221,49.846275C35.580275,53.706753 39.450392,56.407085 43.980528,56.457092 50.230719,56.517097 55.340876,51.496479 55.400877,45.245708 55.470881,39.004938 50.450728,33.884306 44.200537,33.824298 43.670519,33.824298 43.150503,33.864304 42.64049,33.924311L42.630488,33.884306C40.950438,34.104332,39.390391,34.694407,38.030348,35.584515L40.200415,37.634769C40.33042,37.754784 40.380419,37.944807 40.310415,38.104826 40.250414,38.274847 40.100412,38.384861 39.920405,38.394863L34.650244,38.674896 29.970102,38.924927 29.940102,38.924927C29.810097,38.924927 29.700094,38.86492 29.61009,38.77491 29.520088,38.674896 29.480087,38.54488 29.510088,38.404863L30.260111,34.234348 31.340143,28.333621C31.370144,28.153599 31.500149,28.013581 31.670155,27.983578 31.850159,27.943573 32.030165,28.013581 32.130167,28.1636L33.86022,30.703914C36.260294,28.9737 39.11038,27.853561 42.200476,27.513519 42.240477,27.503518 42.280478,27.503518 42.320479,27.503518 42.590487,27.473515 42.850496,27.453512 43.120504,27.43351 43.310507,27.418509 43.500513,27.408506 43.691771,27.403506z M2.9499468,18.059961L44.308165,18.059961C45.938101,18.059961,47.268,19.380206,47.268,21.020318L47.268,21.830486C45.968126,21.610486 44.638106,21.470574 43.278181,21.470575 34.818579,21.470574 27.428881,25.931133 23.269024,32.611961L2.9499468,32.611961C1.3200119,32.611961,-1.251392E-07,31.291716,0,29.661614L0,21.020318C-1.251392E-07,19.380206,1.3200119,18.059961,2.9499468,18.059961z M8.6996557,3.927825C6.8497344,3.927825 5.3397986,5.4269943 5.3397986,7.2759705 5.3397986,9.1249466 6.8497344,10.634111 8.6996557,10.634111 10.549576,10.634111 12.049512,9.1249466 12.049512,7.2759705 12.049512,5.4269943 10.549576,3.927825 8.6996557,3.927825z M2.949901,0L44.308134,0C45.938063,0,47.268007,1.3292637,47.268007,2.9583616L47.268007,11.603574C47.268007,13.232672,45.938063,14.551941,44.308134,14.551941L2.949901,14.551941C1.3199705,14.551941,2.6895254E-05,13.232672,2.6147463E-05,11.603574L2.6147463E-05,2.9583616C2.6895254E-05,1.3292637,1.3199705,0,2.949901,0z" 
                    Stretch="Uniform" Width="26" Height="26" Margin="0,0,0,0" RenderTransformOrigin="0.5,0.5"
                    Style="{DynamicResource ResourceKey=pathButtonStyle}" &gt;
                  &lt;Path.RenderTransform&gt;
                      &lt;TransformGroup&gt;
                          &lt;TransformGroup.Children&gt;
                              &lt;RotateTransform Angle="0" /&gt;
                              &lt;ScaleTransform ScaleX="1" ScaleY="1" /&gt;
                          &lt;/TransformGroup.Children&gt;
                      &lt;/TransformGroup&gt;
                  &lt;/Path.RenderTransform&gt;
              &lt;/Path&gt;
          &lt;/Grid&gt;
  
          &lt;!-- Contenu du bouton "Delete" --&gt;
          &lt;Grid x:Key="pathDelete"&gt;
              &lt;Grid Name="deleteBackgroundGrid" Width="48" Height="48" Visibility="Collapsed" /&gt;
              &lt;Path Data="M2.8803511,35.504998L25.562742,35.504998 25.461922,35.769711C24.680624,37.899521 24.254,40.199002 24.254,42.596199 24.254,44.993397 24.680624,47.292763 25.461922,49.42239L25.563091,49.688 2.8803511,49.688C1.2905214,49.688,-1.9703777E-07,48.395962,2.2562905E-14,46.807518L2.2562905E-14,38.382981C-1.9703777E-07,36.794033,1.2905214,35.504998,2.8803511,35.504998z M38.677929,34.116001L35.216003,37.578362 40.677326,43.039303 35.216003,48.500141 38.677929,51.962002 44.139351,46.501164 49.600777,51.962002 53.062004,48.500141 47.600876,43.039303 53.062004,37.578362 49.600777,34.116001 44.139351,39.576943z M44.126499,27.625C52.394669,27.625 59.098,34.325222 59.098,42.596249 59.098,50.859478 52.394669,57.564999 44.126499,57.564999 35.858036,57.564999 29.156,50.859478 29.156,42.596249 29.156,34.325222 35.858036,27.625 44.126499,27.625z M2.8803511,17.594002L43.182117,17.594002C44.771912,17.594002,46.061001,18.883038,46.061001,20.471483L46.061001,22.815359 45.653645,22.779068C45.149654,22.740591 44.640469,22.720999 44.126797,22.720999 37.278542,22.720999 31.227795,26.204043 27.652769,31.491766L27.471674,31.774002 2.8803511,31.774002C1.2905214,31.774002,-1.9703777E-07,30.484967,2.2562905E-14,28.893622L2.2562905E-14,20.471483C-1.9703777E-07,18.883038,1.2905214,17.594002,2.8803511,17.594002z M8.4794798,3.8200004C6.6786065,3.82 5.211,5.2858002 5.2109985,7.0880244 5.211,8.8926909 6.6786065,10.356001 8.4794798,10.356001 10.281624,10.356001 11.748,8.8926909 11.748,7.0880244 11.748,5.2858002 10.281624,3.82 8.4794798,3.8200004z M2.8803511,0L43.182117,0C44.771912,1.7200194E-07,46.061001,1.2890874,46.061001,2.8775013L46.061001,11.302039C46.061001,12.893373,44.771912,14.18,43.182117,14.180001L2.8803511,14.180001C1.2905214,14.18,-1.9703777E-07,12.893373,2.2562905E-14,11.302039L2.2562905E-14,2.8775013C-1.9703777E-07,1.2890874,1.2905214,1.7200194E-07,2.8803511,0z" 
                    Stretch="Uniform" Width="26" Height="26" Margin="0,0,0,0" RenderTransformOrigin="0.5,0.5"
                    Style="{DynamicResource ResourceKey=pathButtonStyle}"&gt;
                  &lt;Path.RenderTransform&gt;
                      &lt;TransformGroup&gt;
                          &lt;TransformGroup.Children&gt;
                              &lt;RotateTransform Angle="0" /&gt;
                              &lt;ScaleTransform ScaleX="1" ScaleY="1" /&gt;
                          &lt;/TransformGroup.Children&gt;
                      &lt;/TransformGroup&gt;
                  &lt;/Path.RenderTransform&gt;
              &lt;/Path&gt;
          &lt;/Grid&gt;
  
          &lt;!-- Contenu du bouton "Exit" --&gt;
          &lt;Grid x:Key="pathExit"&gt;
              &lt;Grid Name="exitBackgroundGrid" Width="48" Height="48" Visibility="Collapsed" /&gt;
              &lt;Path Data="M34.201,35.752792L36.154999,37.072937 36.154999,61.028999 26.27,61.028999 26.27,58.465 34.201,58.465z M18.94405,30.222998C17.962244,30.222998 17.167,31.018967 17.167,32.00045 17.167,32.982033 17.962244,33.778 18.94405,33.778 19.925556,33.778 20.721001,32.982033 20.721001,32.00045 20.721001,31.018967 19.925556,30.222998 18.94405,30.222998z M44.257435,25.653L44.257435,29.183289 51.842999,29.183289 51.842999,35.705292 44.257435,35.705292 44.257435,39.237999 34.201,32.444984z M26.27,3.8619995L36.154999,3.8619995 36.154999,27.81745 34.201,29.137484 34.201,6.2989998 26.27,6.2989998z M24.27,0L24.27,64 0,60 0,4.0000029z" 
                    Stretch="Uniform" Width="26" Height="26" Margin="0,0,0,0" RenderTransformOrigin="0.5,0.5"
                    Style="{DynamicResource ResourceKey=pathButtonStyle}"&gt;
                  &lt;Path.RenderTransform&gt;
                      &lt;TransformGroup&gt;
                          &lt;TransformGroup.Children&gt;
                              &lt;RotateTransform Angle="0" /&gt;
                              &lt;ScaleTransform ScaleX="1" ScaleY="1" /&gt;
                          &lt;/TransformGroup.Children&gt;
                      &lt;/TransformGroup&gt;
                  &lt;/Path.RenderTransform&gt;
              &lt;/Path&gt;
          &lt;/Grid&gt;
  
          &lt;!-- Contenu du bouton "Save" --&gt;
          &lt;Grid x:Key="pathNext"&gt;
              &lt;Grid Name="nextBackgroundGrid" Width="48" Height="48" Visibility="Collapsed" /&gt;
              &lt;Path Data="F1M1568.35,1934.42L1551.46,1917.44 1551.46,1925.43C1517.67,1925.43 1515.02,1945.4 1515.02,1949.39 1522.31,1933.42 1551.46,1941.4 1551.46,1941.4L1551.46,1949.39 1568.35,1934.42z" 
                    Stretch="Uniform" Width="26" Height="26" Margin="0,0,0,0" RenderTransformOrigin="0.5,0.5"
                    Style="{DynamicResource ResourceKey=pathButtonStyle}"&gt;
                  &lt;Path.RenderTransform&gt;
                      &lt;TransformGroup&gt;
                          &lt;TransformGroup.Children&gt;
                              &lt;RotateTransform Angle="0" /&gt;
                              &lt;ScaleTransform ScaleX="1" ScaleY="1" /&gt;
                          &lt;/TransformGroup.Children&gt;
                      &lt;/TransformGroup&gt;
                  &lt;/Path.RenderTransform&gt;
              &lt;/Path&gt;
          &lt;/Grid&gt;
  
          &lt;!-- Contenu du bouton "Save" --&gt;
          &lt;Grid x:Key="pathSave"&gt;
              &lt;Grid Name="savebackgroundGrid" Width="48" Height="48" Visibility="Collapsed" /&gt;
              &lt;Path Data="M8.1099597,36.94997L8.1099597,41.793968 39.213959,41.793968 39.213959,36.94997z M12.42,0.049999889L18.4,0.049999889 18.4,12.252 12.42,12.252z M0,0L7.9001866,0 7.9001866,14.64218 39.210766,14.64218 39.210766,0 47.401001,0 47.401001,47.917 0,47.917z" 
                    Stretch="Uniform" Width="26" Height="26" Margin="0,0,0,0" RenderTransformOrigin="0.5,0.5"
                    Style="{DynamicResource ResourceKey=pathButtonStyle}"&gt;
                  &lt;Path.RenderTransform&gt;
                      &lt;TransformGroup&gt;
                          &lt;TransformGroup.Children&gt;
                              &lt;RotateTransform Angle="0" /&gt;
                              &lt;ScaleTransform ScaleX="1" ScaleY="1" /&gt;
                          &lt;/TransformGroup.Children&gt;
                      &lt;/TransformGroup&gt;
                  &lt;/Path.RenderTransform&gt;
              &lt;/Path&gt;
          &lt;/Grid&gt;
      &lt;/ResourceDictionary&gt;
  &lt;/Application.Resources&gt;
  </code></pre>
  
  <p>and I consume them like this:</p>
  
  <pre><code>&lt;telerik:RadButton x:Name="rbCancel"
                                 MinWidth="48" MinHeight="48" 
                                 Style="{DynamicResource ResourceKey=cancelButtonStyle}"/&gt;
  </code></pre>
  
  <p>I open my dialog like this:</p>
  
  <pre><code>wpfMaintenanceInspectionType wnd = new wpfMaintenanceInspectionType();
          wnd.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterScreen;
          wnd.ShowDialog();
          wnd = null;
  </code></pre>
  
  <p>So, the first time I display the dialog, all work well but the next times, the <code>pathButtonStyle</code> does not work anymore. When I enable, mouse over the buttons, nothing happen</p>
  
  <p>What's wrong with my code?</p>
  
  <p>--- UPDATE 1 ---</p>
  
  <p>If I put the style in a ResourceDictionary file (ButtonStyles.xaml), and add it to my dialog in his ctor, every work well.</p>
  
  <pre><code>ResourceDictionary dic = new ResourceDictionary();
          Uri u = new Uri("pack://application:,,,/BuildingInspector;component/Resources/ButtonStyles.xaml", UriKind.Absolute);
          dic.Source = u;
          this.Resources.MergedDictionaries.Add(dic);
  </code></pre>
  
  <p>Why it does not work with the style defined in the app.xaml?</p>
  
  <p>--- UPDATE 2 ---
  The dialog is build from a base class <code>appClass:CBIBaseRadWindow</code>
  And the base class inherits from RadWindow <code>public partial class CBIBaseRadWindow : RadWindow</code></p>
  
  <p>--- UPDATE 3 ---
  I try a new thing: I have created a new dialog, with only a button, a click on the button creates a new instance of this new dialog. Result:</p>
  
  <blockquote>
    <p>At start, the first instance work well, image appears and triggers(IsPressed, IsMouseOver) work well
    As soon as I click on the button, a new dialog appears with the image but:
    - The triggers don't work on this dialog
    - The image on the first instance disappears
    - The triggers on the first instances apply on the second instance (if I pressed the button of the first instance, the color change on the second instance)</p>
  </blockquote>
  
  <p>It's like the style couldn't be applied on several instances??</p>
  
  <p>--- UPDATE 4 ---
  <a href="http://www.abhisheksur.com/2011/07/internals-of-dependency-property-in-wpf.html" rel="nofollow">Internals of Dependency Property in WPF</a>
  After reading this article, I think that the problem is my dependency properties. They are defined in the global style:</p>
  
  <pre><code>&lt;Style x:Key="cancelButtonStyle" 
                 BasedOn="{StaticResource ResourceKey=defaultButtonStyle}" 
                 TargetType="{x:Type telerik:RadButton}"&gt;
              &lt;Setter Property="app:DependencyProperties.ImagePath" Value="{DynamicResource ResourceKey=pathCancel}" /&gt;
              &lt;Setter Property="app:DependencyProperties.Color" Value="Salmon" /&gt;
              &lt;Setter Property="app:DependencyProperties.MouseOverColor" Value="SandyBrown" /&gt;
              &lt;Setter Property="app:DependencyProperties.PressedColor" Value="Red" /&gt;
          &lt;/Style&gt;
  </code></pre>
  
  <p>and because of that, maybe, as soon as a second instance is created, the first lost something.</p>
  
  <p>Can someone can confirm/infirm this?</p>
  
  <p>Thanks </p>