Comment 92 for bug 444139

update after upgrading to lucid:

KMS is now getting turned on automatically (I can see it in my dmesg output), and so the bug is fixed from the standpoint that I no longer get a black background and no full screen apps. I do still get artifacts, but so far (a little less than a day) no freezes, so desktop effects are at least usable (before, i had a choice between black background or occasional freezes).

The other, larger problem, is that I now have horrible performance when scaling a video to fullscreen with desktop effects on. With desktop effects off, fullscreen video works, but video performance otherwise (most noticeably moving windows) is terrible.

I do not believe I had this problem under karmic when I set both KMS and desktop effects on, but I never tested for it specifically.