Comment 46 for bug 85370

amd64 desktop running 32bit mainstream ubuntu, confirmed no hangs after disabling powernowd.
funny enough before disabling that init script, solution would be to go to text console after gdm started, and to type there some meaningless(for this case) commands like ps and ls, probably giving the driver some time to finish initialization or whatever. otherwise computer hangs during the gnome start or just after.