With my i845, I lost direct rendering after upgrading to Edgy. My desktop resolution is 1280x1024, but I was able to solve my problem by removing "1600x1200" from the resolution lines in my xorg.conf. It seems possible that if it can't get direct rendering in the highest resolution, it won't try in the lower resolutions.
-- performance issue in Edgy with i810 driver https://launchpad.net/bugs/61306 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs