When some one is in Battle Room and Alt+TABs back to PW lobby and PMs someone, he is not able to receive any PMs. The other guy sending those PMs to the person who is f.e. hosting an igw doesnt know that the guy hosting/ingame doesnt get those PMs.. So there should be a message, or it should / shouldn't be possible to PM a person in Battle Room. I hope you dont understand a word