Periodically, on both Parallels 4 and 5, some of the applications that were running on Parallels get "stuck" on the dock because the "Application Is Not Responding." The only option is to force quit but this does nothing. Restarting the program and shutting down Parallels does nothing as well. The only thing that I can figure out to clear the icon from the dock is restarting the computer. This has happened on both my Macbook Pro and MacBook Air. Any fixes for this?