When I switch to presentation mode, it freezes the application and sometimes causes it to close.  I have tried removing all service layer connections (even the base map) and it still freezes.  I am using a custom extension, but there are no events being triggered or any logic being run by it.  
Any ideas?  :confused:
Could it have anything to do with the video drivers?  I have two separate machines, and it only freezes on one of them.