Okay, I think this thread is the best match for my symptoms. On boot, after the second set of beeps, I expect to see the MCE interface, but instead, I see a blank (black or empty) screen with a (working) mouse pointer in the middle. It's as if you loaded XWindows without any window manager and the desktop was solid black.
If I login to console 1 (Ctrl-F1) and run 'sudo screen -r' I get a this:
There are several suitable screens on:
10160.XWindowSystem (02/12/2009 01:00:59 PM) (Detached)
8983.SambaRadar (02/12/2009 01:00:52 PM) (Detached)
8971.StorageStatusRadar (02/12/2009 01:00:52 PM) (Detached)
8740.SambaRadar (02/12/2009 01:00:50 PM) (Detached)
8111.BkgSS-UpdateMediaDaemon.sh (02/12/2009 01:00:46 PM) (Detached)
6301.VoiceMailMonitor (02/12/2009 01:00:28 PM) (Detached)
6284.NewMDinteractor (02/12/2009 01:00:28 PM) (Detached)
6276.DhcpdPlugin (02/12/2009 01:00:28 PM) (Detached)
Type "screen [-d] -r [pid.]tty.host" to resume one of them.
I can quit whatever is running on virtual console 7 with Ctrl-Alt-Backspace, like X. I can then restart KDE or re-run the AVwizard (which works perfectly well) with the appropriate script in the /usr/pluto/bin directory. But, the latter doesn't seem to have any effect on my symptoms.
The system was working, previously, but video was a little choppy. So, I installed the nVidia proprietary driver. (I tried to install it before running the RC2 scripts on top of my fresh KUbuntu install, according to the instructions. But, the KDE tool is a little funky and I didn't do it right.) Since that was the last thing (I remember) tweaking before it stopped working, I uninstalled the proprietary driver, but that didn't fix it.
Any thoughts on where to go from here? What is screen telling me?