virtualbox.org

I've been having my Ubuntu 8.10 guest on my Ubuntu 10.04 host get stuck in a black screen. I'm running 3.2.0 PUEL w/ guest additions, more details at end.

The first time happened overnight. I didn't know to try core-dumping it per the HOWTO, and I just killed the VM (VBox itself was still operational).

The second time this happened was after attempting seamless mode. The Host+Home combo didn't work to bring up the VM menu, so I exited seamless mode, and it was all black again (host window drawing gets left there). This time, I saw the Insert Ctrl-Alt-Backspace command, and that indeed worked, kicking me out to the login screen.

Then I got on the forums and found this post, which mentions an xorg config. I looked in my guest's and it looks the same as the HOWTO, except that it's missing the line:
Driver "vboxvideo"

Could that be the source of my problems, or is it likely to be something else?

If you have installed the guest additions (in the guest) IIRC it should have edited you xorg.conf to include that line in Ubuntu 8.10
If not this could be a problem and the inclusion should help. Be sure to make a backup of the original xorg.conf in case everything goes bad so you can recover.

I added that line to my xorg.conf, and now seamless mode seems to work well. Hopefully the black screens will go away too.