Is there any other way to solve my problem?
Thanks for your help.
Please install the nvidia driver via ubuntu packages, and make sure that no manually installed or envy installed drivers are there. Please also remove the failsafe Xorg config in /etc/X11/ if it is there. Then:
`sudo /etc/init.d/gdm stop`
log in on a VT (CTRL+ALT+F1, you should be there anyway after quitting gdm)
`startx -- -logverbose 5`
(which should fail)
then change the /etc/X11/xorg.conf to use vesa or nv, and start up gdm again.
You can then upload the nvidia bug report file, plus the /var/log/Xorg.0.log.old (or similar) to a post here, so we can try to find and solve your problem.