I have the exact same problem with a Dell 640m (Intel 945GM + 1440x900 lcd). Ubuntu Edgy and currently Feisty too are unusable out of the box.
-- Installer X server startup fails https://launchpad.net/bugs/62002 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
