Ok, seems to be a known bug then. Also had this "empty message box" after I had to restart the game issue at the radio station. It actually worked the first time I started the game. Then it just didn't work anymore, after I had to "quit" and "start" the game due to the falling throught the floor bug. I just tried to reproduce it... The bug happens if you ESC -> quit -> start ... hence there is something in that "quit" or "reset everything" routine that's missing or messing things up. Hope that helps to find this one.
