Several weeks ago, we had a power outage, and when my laptop came back
up (I run it 24/4 without batteries) the display was running in CGA
resolution. I found that my display driver had somehow been disabled.
I got it working again (more or less) but now, my desktop is larger
than my display. I have to move the mouse over to the corner of the
display to see the icons, and then move it down to the bottom of the
display to see the taskbar.

The machine is a Toshiba Satellite 2455-S305 and the graphics
controller is an nVIDIA GeForce4 429 Go. When I first installed Ubuntu
on this machine, I had a lot of trouble finding the right driver to
download.

Any suggestions?