Comment 37 for bug 257894

I'm seeing this same problem on a Toshiba Satellite U205-S5057. The VGA screen goes black anywhere from a few seconds to several hours after I log in. (For the longer times, the VGA output flickers horizontally every so often; I'm not sure what the time interval is.) I noticed that daemon.log shows scim-bridge quitting right before the display goes black (see below), and this behavior started around the time that I enabled scim-bridge, so I will see if disabling it fixes the problem. I could be a coincidence, though, because I also got some updates around the same time. Is anyone else here using scim-bridge and seeing similar output in daemon.log?

Additionally, when the VGA screen goes black, I use
xrandr --output LVDS --auto
to turn the built-in screen back on. When I try
xrandr --output VGA --off
I get dumped back to the login screen as if I had hit ctrl+alt+backspace.

Here is the lspci output relating to the onboard video:
00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)

Here is the output from /var/log/daemon.log. The second line through the last represents the window during which the VGA output went black, and probably up to the point where I was back at the login screen. The last line is the end of the log.
Feb 3 20:10:39 thelaptop scim-bridge: Cleanup, done. Exitting...
Feb 4 00:17:54 thelaptop scim-bridge: Cleanup, done. Exitting...
Feb 4 00:17:55 thelaptop kdm[5409]: X server for display :0 terminated unexpectedly
Feb 4 00:17:55 thelaptop console-kit-daemon[5175]: WARNING: Unable to activate console: No such device or address
Feb 4 00:17:55 thelaptop acpid: client connected from 15919[0:0]
Feb 4 00:18:00 thelaptop acpid: client has disconnected
Feb 4 00:18:03 thelaptop kdm_greet[15959]: Cannot open default user face

Also, /var/log/Xorg.0.log shows a lot of these:
(EE) intel(0): underrun on pipe A!
but there's no time to correlate it with the daemon.log output.