More testing with above config.... I am getting inconsistent results. Seems to work for minutes with multiple stops, then occasionally hangs.
So to confirm, it really freeze, can you try to switch with ALT++ENTER (full to window or window to full), be doing that the skin engine is reset and i'm pretty sure the GUI will be back, if not it's really a deadlock and MP is freezed and you have to kill it.
The GUI is not really freeze. ALT+ENTER resolves the GUI issue.
My guess (90+% confident) is that this error is the reason for that:2. Blackscreen on all live TV.