In Telerik's WP7 example, if you modify the PhoneApplicationFrame > Wizard > TileTransitionStartPage.xaml to the following,
//MainViewModel.Instance.MainFrame.Navigate(new Uri("/PhoneApplicationFrame/Wizard/TileTransitionEndPage.xaml", UriKind.RelativeOrAbsolute));
EmailComposeTask email =
"WP7 Own This World Support"
"Hey BNID Admin, I'm having an issue with Own This World..."
Then, double tap, or tap 2 times quickly it will crash. (This is on 2011 Q1 SP1 as well).
If you put a try/catch around the EmailComposeTask, it will catch it, however I think the underlying problem is the animation is taking the tap a 2nd time causing the call again, which errors out because the current window is now the email window.
Let me know if you still want a small project.