Ok,

I don't know which component is actually responsible for this issue, but I've had this problem for a year now (In Gnome 3.2 or 3.1 in Fedora 16) and now with Gnome 3.4.x in Fedora 17 (64bit).

When using Gnome 3 in graphics fallback mode this issue does not occur. It only occurs when using Gnome 3 with shell enabled.

So the problem occurs when using VMWare player (windows xp installed with vmware tools, including vmwares display driver for virtualized os). It does not matter if Im playing a game or just having virtual machine on, but randomly the whole system freezes. The sound keeps playing normally, and mouse cursor can be moved freely, also you can switch to terminal mode and back, however everything remains frozen. The shell, windows, graphics within windows, nothing updates. Except sound and mouse cursor. Forceful reboot is required.

Ive also noticed that freezes happen most often when using notifications on bottom and opening activities panel.

To re-create this problem yourself, install Fedora or any other OS with Gnome Shell 3.x and than use VMWare player 4.0.x and within an hour you will have a guaranteed crash.

I dont think this is the driver issue (I have proprietary nvidia drivers).