Comment 3 for bug 506444

I can confirm this, it looks like the screen is shaking up and down very shortly.
I don't know if it's related, but I get this all the time:
Jan 15 15:44:47 helios kernel: [ 1006.048114] Skipping EDID probe due to cached edid
Jan 15 15:44:47 helios kernel: [ 1006.130362] [drm] TV-16: set mode NTSC 480i 0
Jan 15 15:44:47 helios kernel: [ 1006.296284] [drm] TV-16: set mode NTSC 480i 0

It also sometimes crashes and the screen is either black or a single color, but this seems to be another bug.

Backtrace:
0: /usr/bin/X (xorg_backtrace+0x3b) [0x80e135b]
1: /usr/bin/X (0x8048000+0x60a8d) [0x80a8a8d]
2: (vdso) (__kernel_rt_sigreturn+0x0) [0xbd3410]
3: /usr/bin/X (DisableDevice+0x21f) [0x80790ef]
4: /usr/bin/X (xf86Wakeup+0x3bd) [0x80b406d]
5: /usr/bin/X (WakeupHandler+0x52) [0x809dfd2]
6: /usr/bin/X (WaitForSomething+0x1aa) [0x80a7c9a]
7: /usr/bin/X (0x8048000+0x49da0) [0x8091da0]
8: /usr/bin/X (0x8048000+0x1ecfa) [0x8066cfa]
9: /lib/tls/i686/cmov/libc.so.6 (__libc_start_main+0xe6) [0x277bd6]
10: /usr/bin/X (0x8048000+0x1e8e1) [0x80668e1]
Segmentation fault at address 0x4

Caught signal 11 (Segmentation fault). Server aborting

00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)
Linux helios 2.6.32-10-generic #14-Ubuntu SMP Thu Jan 7 17:38:40 UTC 2010 i686 GNU/Linux
xserver-xorg-video-intel 2:2.9.1-1ubuntu1