I can reproduce the crash always in the following way:
1) Boot the machine.
2) Log in to KDE. Everything works, including 3d effects.
3) Log out of KDE. KDM starts.
4) Log back in -> X crashes, KDM restarts immediately.
5) Log in again -> KDE disables 3d effects and allows logging in.
Sometimes if I try to enable effects after 5), I can crash X again. But that does not happen every time.
It also might be relevant that I can reproduce the crash on both my desktop machine and my laptop, both of which are running Oneiric and both of which have Intel integrated graphics. I have not seen similar behavior with my work desktop, which has discrete nVidia graphics.
uname -a: Linux desktop 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2 13:27:26 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
lspci graphics information: 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12)
Intel X driver version: 2:2.15.901-1ubuntu2.1
Some more information.
I can reproduce the crash always in the following way:
1) Boot the machine.
2) Log in to KDE. Everything works, including 3d effects.
3) Log out of KDE. KDM starts.
4) Log back in -> X crashes, KDM restarts immediately.
5) Log in again -> KDE disables 3d effects and allows logging in.
Sometimes if I try to enable effects after 5), I can crash X again. But that does not happen every time.
It also might be relevant that I can reproduce the crash on both my desktop machine and my laptop, both of which are running Oneiric and both of which have Intel integrated graphics. I have not seen similar behavior with my work desktop, which has discrete nVidia graphics.
uname -a: Linux desktop 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2 13:27:26 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux 901-1ubuntu2. 1
lspci graphics information: 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12)
Intel X driver version: 2:2.15.