Every couple of days, the Unity (Ubuntu 12.10) on my laptop (DELL Latitude 6510) freezes. I cannot get any response from the desktop. If I switch to a text terminal (Ctrl-Alt-F1) and switch back (Ctrl-Alt-F7), the desktop unfreezes but the Unity launcher, the top panel, and the title bars of the windows all disappear. Logging out (with Ctrl-Alt-Delete) does not solve the problem; a restart is needed. All the logged-in users are affected by this.
From the apport error messages I get, it looks like it is related to a GPU lockup and the package xserver-xorg-video-intel is implicated.
Does anyone have any ideas that can help with my problem?
Please let me know if I can provide more information that will be useful in diagnosis.