I`m having the same problem.
I load the map, press the join button, and my FH Spawn select screen freezes, my mouse wont move, my keyboard won`t work on FH, but I can see the chat on the server going through..
When I press the CTRL + ALT + Del I can get out of the game, my mouse returns to move on the screen..
I tested it on a Internet server and on a local server, the error persists..
Tryed reinstalling FH, the 1.5 Patch.. nothing works..
It worked fine for 2 days, after that it went like that..