Comment 3 for bug 751735

I'm also affected. I am using Shuttle SG33M with LCD TV connected to HDMI output. Important lspci lines:

VGA compatible controller: Intel Corporation 82G33/G31 Express Integrated Graphics Controller (rev 02)
Display controller: Intel Corporation 82G33/G31 Express Integrated Graphics Controller (rev 02)
Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02)

Ubuntu 10.10 and previous versions all worked fine. Ubuntu 11.04 shows bad colors (after upgrade and reboot). Fresh 11.04 install CD also shows bad colors on installation screens as well. The LCD TV is constantly connected and always shows bad colors after first modeswitch. Same thing happens if I switch the TV on later.

Most of the colors are from green to bright white with some light purple. Black color is shown green, red is shown the same green, green is shown light green, blue is shown as black. I don't know what combination causes white and purple. The image does not seem to have any extra noise or pixels that should not be there. Only the colors which are changed always the same way I've described.