It seems that it was a bug in input subsystem of xorg and not in device driver. Resent xorg updates fixed the issue - there was no useful info in kdm error log any more after crashes - but config files were corrupted. Thanks to dpkg-reconfigure magic the problem is finally gone - uptime for ~3 days without crashes.
** Changed in: xorg (Ubuntu) Status: Incomplete => Fix Released -- xserver-xorg periodically segfaulting after upgrade to 8.04 https://bugs.launchpad.net/bugs/229276 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs