While not the same problem or solution that the original poster
reported, I have had two weird things happen on my 8.10 system since I
last reported no problems.

Several times I have walked away from the computer, and come back to
find Firefox blank, both the address bar and the main window. When I
clicked on the "Home" icon, all was well. I restarted Firefox several
times, and had this happen after restarts.

Later, I was listening to Rhythmbox, and editing an email, and the
sound stopped. About a half second later, the screen went mostly black
with some colored lines and a bit of colored snow.

I could successfully switch to a VC with ctrl-alt-F1, and from there I
checked with ps and gdm was still running. I tried an "/etc/init.d/gdm
restart", this resulted in gdm running twice, and a screen that said
that Ubuntu was being started in low graphics mode. I killed both
copys of gdm with "kill" and then "kill -9" and restarted gdm again. I
got the low graphics message again.

I had an email I needed to send, so I just said the heck with it and
rebooted. All was well, and has been since, that was about 36 hours
ago, and Firefox has not done anything unexpected either.