11.10 Guest Session, Blank screen, computer hangs.

This upgrade to 11.10 on my desktop hasn't been easy.:(

If I try to access a guest session from either the login screen or from within a Unity session I get a completely black screen and can do nothing, having to press the reset button on my pc to get things working again.

Anyone have any idea how I can resolve this?

Vic

http://ubuntuforums.org/showthread.p...n+blank+screen

Others are having same issue. Haven't found a response. Are you using an ATI Radeon Video Card?