Screen Goes Black

I did a fresh install of OpenSuse 12.1 64 bit (KDE) yesterday. Everything went fine but today I’ve started to experience an apparently random problem.
I’ll have a window(s) open, file browser, web browser etc, it doesn’t make any difference what or how many. Then I notice instead of the panel and desktop, everything behind the active window has gone completely black. I close the open window and am left with a totally black screen, my mouse cursor is still visible and moves. I press cntrl-alt-delete and up comes the Logout/Shut Down window. I click on Log out then the log in window appears a short time after. I log back in and everything’s fine again.
I haven’t made any changes to the graphics system and am using whatever graphics driver came with the install. I haven’t got anything other than the default desktop effects enabled.
I replaced a Fedora 16 64 bit KDE install with OpenSuse and never encountered this with Fedora.
My graphics card is an ATI Radeon HD 5750. I’m dual booting with Win 7 and this doesn’t happen when I’m using Windows so I can’t see that it’s a hardware issue.
If anyone can advise me I’d appreciate it before I go back to Fedora.
I don’t have a sceensaver enabled and I’ve checked in the power settings (which are all at default for a desktop PC) to see if there was anything there that may be causing it.

It’s plasma-desktop crashing. If you do “Alt-F2” then enter “plasma-desktop”., things should return to normal. But that’s just a fix, not a solution. To find out what’s happening, you need to look through /home/YOURUSERNAME/.xsession-errors.

Question: did you install the ATI proprietary driver?


Thanks for the reply. Last question first, no I’m using the default driver that came with the install and not made any changes to the graphics settings.

Is there anything in particular that I should be looking for in .xsession-errors, it’s a long document and doesn’t seem to have any date ordering so I can’t locate the time period when it last happened.