"I can ssh into the frozen box as well. I am pretty sure it has something to
do with the nvidia binary drivers and or xorg 7.2. i have already stated
this once but I have installed both the 9755 and the latest beta 100.xx.xx
and they both have the same stupid freezing of very simple progream like
gedit or even editing my menu thru system, prefs, or even when I tried to
open up the network dialog box. then I can force quit the frozen apps, and
still can use FF and terminal for a small amount of time, then nothing but
moving the mouse works, can't even do ctrl-alt-f1 but I can still ssh into
the box. it's very weird that I can't even go to another tty using
ctrl-alt-f1 or even shutdown xserver trying crtl-alt-backspace. I sure hope
this doesn't happen with the nv driver as I at least want better graphics
than vesa. i didn't think trying to get openGL or Direct rendering would be
that hard to get to work with a GeForce 6200 128mb. this is getting insane."

#166 at http://ubuntuforums.org/showthread.php?t=412125&page=17