Comment 3 for bug 762918

I have a similar issue on my Dell Vostro V13; in fact, certain screensavers have been sluggish ever since the upgrade to natty, notably "Helios" - there was no such issue on Maverick. Also notable is the point that I have observed no such issue on my Sony Vaio VGNAR520E, which has also been upgraded to natty. The Vaio has an nvidia GeForce 8400, while the V13 has the onboard intel video, which might be related to the issue. When the screen freezes, I can log onto a virtual console using Alt + Ctrl + F1 and issue "sudo pkill X" from there to restart the X server, at which time gdm loads and allows me to log-in.

The freezing occurs with any screensaver as far as I have noticed - sluggish or not; Helios was visibly bad; Hufo's Tunnel is normal but it freezes similarly.