Comment 51 for bug 320771

(In reply to comment #32)
> Well, I have to add something here.
>
> Shortly after the corruption appeared (around an hour or so) the cursor changed
> into a square as I moved the cursor from one screen to the other. Additionally
> the cursor moved with a delay and not smooth at all. After that the keyboard
> was inaccessible and logging in via SSH remotely (which took quite some time) I
> saw that Xorg was using almost all CPU (dual-core AMD X2) and what I was
> curious about was that even 'top' was using very much CPU (~20-60%).
>
> The system didn't come down correctly after issuing a 'shutdown now' so I had
> to hard-reset the system.
>
> Although the mouse pointer was movable (hardware cursor) the system didn't
> respond to anything.

That's a GPU lock-up.