computing locks up while switching users

Hello,

In the past 4 days my computer has started to lock up when I switch users. The keyboard is still active, but my screen goes blank and nothing but manually shutting it down works. My display drivers are up to date. I'm running vista business x64. Anyone run into this before?

Thanks! Any suggestions would be appreciated.

Try to update the drivers of your graphics card, mainly if you run a Nvidia card.