Ubuntu Lucid: Restarting X Server

Strangely, on my desktop computer, sometimes the Nvidia driver doesn't get used properly on startup or restart, resulting in an ultra low display resolution.  This sometimes occur, and sometimes doesn't.  Very frustrating.

Fortunately, a one-shot solution is just to restart the X Server.  Go to a terminal, eg, by keying Ctrl-Alt-F7 to go to a tty after reaching the log-in screen at startup.  Then do sudo restart gdm.

This requires that you can use sudo of course.  At least with Ubuntu, that's the same as doing sudo /etc/init.d/gdm restart.

On startup, Ubuntu does detect the problem and offers a choice to restart the X server, but that somehow doesn't work.  Doing this manually at a terminal does though.  Weird.