Disabling Sync to VBlank compiz option *seems* to workaround this to me... However it's totally a driver bug to be fixed.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/762918 Title: Natty Screensaver freezes system after some period of inactivity -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs