I've got the same problem running Edgy Xubuntu on a Powerbook G4 1.5 ghz w/Radeon Mobility 9600. My glxinfo also reports direct rendering to be: "Yes". Compositing is turned off. I also ran gentoo on this machine some months ago with working direct rendering.
-- 3d rendering performance regression Dapper->Edgy with Radeon 9600 M10 https://launchpad.net/bugs/61607 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
