In my case situation improved a lot removing the /etc/X11/xorg.conf file and following the advices here :
https://wiki.ubuntu.com/X/Troubleshooting/FglrxInteferesWithRadeonDriver#Problem:%20%20Need%20to%20fully%20remove%20-nvidia%20and%20reinstall%20-nv%20from%20scratch -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/768275 Title: Compiz effects slow and laggy on Natty with ATI card -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
