Blender crashes when I work in perspective mode.

I'm new to ubuntu, so this is probably obvious, but whenever I switch blender to perspective mode and then I try to do anything it crashes and I'm logged out of my computer! I have to log back in and all my programs are closed. I suppose its a problem with the graphics driver. I have an ATI Radeon mobility 200m and I installed the ati binaries from the add software > system tools menu, but no luck. Has anyone else had this problem?