Ubuntu
linux-restricted-modules-2.6.20 package

  1. Bug #106434
  2. Comment #21

Comment 21 for bug 106434

Revision history for this message
Sitsofe Wheeler (sitsofe) wrote : Re: 2.6.20-15-generic breaks X when using NVIDIA-glx drivers

Doh, I've only just realised that you said you manually installed the nvidia drivers at some point in the past:
"Actually even vanilla Nvidia driver from nvidia installer does not load with -15. Manually running modprobe nvidia gives FATAL: could not run install command for module or such." I wish I'd spotted this sooner because as soon as you go the manual route any problems that arise may be beyond Ubuntu's control and you are better off reporting issues to NVIDIA via http://www.nvnews.net/vbulletin/forumdisplay.php?f=14 .

The fact that the lowlatency kernel works but the regular kernel doesn't suggests the manual binary driver install has overwritten/created a kernel module that interferes with the default Ubuntu provided kernel module. If the X server works with the binary driver after doing:
rmmod nvidia
modprobe nvidia_new
Then that will confirm the problem and there might be a way to use the default Ubuntu modules again.