Gnome failed to start automatically on reboot
 

I've just installed the new NVidia graphical driver (because the gnome wasn't starting).
Now, when I reboot the system, the gnome doesn't start, and gives sometimes a blue screen (no it isn't Windows, its a RedHat 9).
To run gnome I have to get out to shell (ALT+F1), logon and type 'startx' and then the gnome starts well.
What can I do to solve this problem???

Thanks

Moacir