Comment 54 for bug 480220

Absolutely the same here for me (i915GM in a Dell D410 used with D-Dock's TV output, Ubuntu 10.04, kernel 2.6.32-27-generic).

After boot I have a stable NTSC output but can switch to PAL using "xrandr --output TV1 --set mode PAL". However, the picture gets unstable then: every time I move the mouse or have a lot of harddrive activity the TV picture jumps up and down, sometimes only some (rectangular) areas of the picture are affected. When there is no mouse movement the picture is stable.

$ xrandr --verbose
...
TV1 connected 1024x768+0+0 (0x4f) normal (normal left inverted right x axis y
...
 1024x768 (0x4f) 26.9MHz *current +preferred
       h: width 1024 start 1025 end 1088 total 1120 skew 0 clock 24.0KHz
       v: height 768 start 769 end 800 total 801 clock 30.0Hz

When I create & use a new modeline with doubled dotclock like this:

$ xrandr --newmode foo 54 1024 1025 1088 1120 768 769 800 801

...I get a stable picture.

BTW: If there is no connection to the TV set at boot time, xrandr will always show "TV1 disconnected" no matter if I plug in the TV out cable or not. Maybe both effects are caused by kernel mode settings. I have to try with disabled KMS.