I'm now using the driver from https://launchpad.net/~xorg- edgers/+archive/drivers-only and that seems to fix the screensaver problem as well.
I'm attaching the current Xorg.0.log ** Attachment added: "Xorg.0.log" http://launchpadlibrarian.net/34358658/Xorg.0.log -- [K8M800] AntSpotlight screensaver causes system to lock up immediately https://bugs.launchpad.net/bugs/455954 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
