title: VSTO Word 2010 getScreentip getSupertip not fired
body: <p>I have a problem with my custom XML Ribbon,
  The callback "onAction", "getImage" and "getEnabled" work perfectly but getScreentip and getSupertip don't work. </p>
  
  <p>XML :</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" onLoad="Ribbon_Load"&gt;
    &lt;ribbon startFromScratch="true"&gt;
      &lt;qat&gt;
        &lt;sharedControls&gt;
          &lt;button id="Flag_fr-FR"
                  onAction="OnActionCallback"
                  getScreentip="GetScreentip"
                  getSupertip="GetSupertip" 
                  getImage="GetImage"/&gt;
          &lt;button id="Flag_en-EN"
                  onAction="OnActionCallback" 
                  getScreentip="GetScreentip" 
                  getSupertip="GetSupertip"
                  getImage="GetImage"/&gt;
          &lt;separator id="Sep1" insertAfterQ="FlagEn"/&gt;
          &lt;button id="Refresh"
                  insertAfterQ="Sep1" 
                  getScreentip="GetScreentip"
                  getSupertip="GetSupertip"
                  onAction="OnActionCallback"
                  getImage="GetImage"/&gt;
          &lt;separator id="Sep2" insertAfterQ="Refresh"/&gt;
          &lt;button id="Search"
                  insertAfterQ="Sep2"
                  getScreentip="GetScreentip"
                  getSupertip="GetSupertip"
                  onAction="OnActionCallback"
                  getImage="GetImage"/&gt;
          &lt;button id="OnScreenKeyboard" insertAfterQ="Search"
                  getScreentip="GetScreentip"
                  getSupertip="GetSupertip"
                  onAction="OnActionCallback"
                  getImage="GetImage"/&gt;
          &lt;button id="Logout" insertAfterQ="OSK"
                  getScreentip="GetScreentip"
                  getSupertip="GetSupertip"
                  onAction="OnActionCallback"
                  getEnabled="GetEnabled"
                  getImage="GetImage"/&gt;
        &lt;/sharedControls&gt;
      &lt;/qat&gt;
    &lt;/ribbon&gt;
  &lt;/customUI&gt;
  </code></pre>
  
  <p>Code-behind :</p>
  
  <pre><code>public String GetScreetip(Office.IRibbonControl control)
   {
       return ("Test...");
   }
  
   public String GetSupertip(Office.IRibbonControl control)
   {
       return ("Test");
   }
  </code></pre>