Lion crashed several times while using LaunchPad and Mission Control

I upgraded my Mac Book Pro [ i7 2.66GHz 8GB RAM ] to OS X Lion 2 days ago. Since then it has crashed several times while using Mission Control and LaunchPad. The screen goes blank and the only way out of it is to power cycle it.

The applications I use while the crashes happen are: Mail, Skype, Safari, VMWare Fusion (of course LaunchPad and Mission Control). Has anyone else seen this?

I reported all crashes to Apple. No response/fixes yet :-(

I love it when it is running ;-) so I do not have any plans to downgrade it back to OS X Snow Leopard.