Is an Opensuse re-installation a possibility for you? That's always been my cure-all. 
Well, I did an "upgrade" install (more like downgrade for that matter), after which everything worked quite fine. Then I installed updates and all the stuff that got deleted through "upgrade" (most notably, KDE 4.2 and the ATI driver; good that my download speed seems to have tripled since last time I checked (holy sh*t, it's over 9000 now! kbitps, that is)), when it stopped working again. As I said, same problem radeonhd (at least I think I tested it). I cannot imagine how the problem is related to KDE 4.2 though, as it appears on X Server startup, in the middle of KDM login, when starting amdcccle and when turning on desktop effects in KDE. I don't even have a clue how these actions might be related.
Have you tried booting to a console (init level 3 so that X windows isn't running at all) and then trying a:
sax2 -r -m 0=fglrx
That tells sax2 to ignore your existing xorg.conf, and try configuring it from scratch using the fglrx driver.
Tried that. It tells me that my previous settings will be ignored and then gives me a blinking cursor until I ^C it. The Sax2 log is empty (if you don't count the header saying that this will be the SaX2 log). X is not even started, xorg.conf is not overwritten. Starting SaX from within X will result in a black screen of death. No crash though; I think it's just a frozen X server not responding to keyboard input. But that has little to do with the problem I think, as I had that problem earlier.
Again about logs: none of them contained any useful information. I have checked X log and kdm log (and stderr shortly after experiencing the bug). No warnings/errors that weren't there before the problem started.
I suppose it's just some broken factory package, though I repeat I would not know which one that could be. All packages starting with xorg- are from official 11.1 stable or update repositories. Well I'll wait if it gets fixed, seeing that I wouldn't be much help as a bug reporter either as I have no clue what is causing it and why. Or In which piece of software the bug is. Also, it isn't that big a deal, only being unable to enable desktop effects and really rare crashes while playing ps (it happened twice).
Thanks for your help anyway
