trouble with logon

hey everyone, just bought the game the expansion and for some reason when i go to logon, the game and my system freezes. i can load the game, get to the logon screen, i log on, the loading screen comes up and as soon as the game comes up, it freezes. And the thing is i logged on to two of my buddies accounts and their's worked flawlessly, and then i go to log on to my account again, and mine freezes again. I'm absolutely clueless on how to solve the problem, if anyone know anything, i could use the help. Thanks.

alot of people have been having problems getting their game to work(including me also)..i think we'll have to wait for this to get fixed