title: Keybinding ALT+C doesn't work
body: <p>I've got some keybindings like</p>
  
  <pre><code>new KeyBinding() { CommandParameter = %param%, Key = %key%, Modifiers = ModifierKeys.ALT  CommandTarget = %content frame%, Command = NavigationCommands.GoToPage });
  </code></pre>
  
  <p>If I use for example <code>%key% = Key.H</code> it's work as expected. Only for <code>Key.C</code> it doesn't work.</p>
  
  <p>Any suggestions? </p>
  
  <p>p.s. after clicking <kbd>ALT</kbd> +<kbd>C</kbd> windows system sound is played</p>