Same here, complete new install of Ubuntu 13.04 on Asus U46SV i5-2410M 2.3 ghz, Sandy Bridge. GPU Hang especially happens frequently when using dual screen setup. Ctrl + Alt + F-something and then switching back again makes the desktop responsive again most times, although occasionally I have to rebbot.
Same here, complete new install of Ubuntu 13.04 on Asus U46SV i5-2410M 2.3 ghz, Sandy Bridge. GPU Hang especially happens frequently when using dual screen setup. Ctrl + Alt + F-something and then switching back again makes the desktop responsive again most times, although occasionally I have to rebbot.