I have also experienced the same problem on my Sony VAIO (VGN22E), It happened both in Ubuntu and Ubuntu classic desktop. It was the floating ubuntu logo and matrix screensavers that I have tried so far.
-- 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