When i join a game with friends everything runs fine...until we open the lobby up to public to let 4 more players join once these players start joining the lobby my game freezes for like 10 seconds then unfreezes for a second then freezes up again.

atm the only way i can play a game is if they start the game and then kick someone and i connect through console and even then when im on the load-up screen it freezes then when it unfreezes the game loads up a bit then freezes then loads a bit etc. so i just have to wait until its fully loaded.

I have Windows Vista....8600gt gfx card....Dual Core @ 3ghz....500gb Hard Drive and 4gb of ram.

The game loads up really fast from start-up and once im in game everything runs smoothly for the most part.

Any ideas what this problem is or how i can fix it please let me know!