loading screen help

Ok...i just got flight deck 4 and installed it on my comp. .....it works great on free flight but once i choose to fly one of the planes it added on multiplayer it screws up...heres what happens...i join a lobby and choose a fighter jet..or any other plane from FD4...i hit ok and it goes to the loading screen..it loads perfectly ...then it gets to "loading multiplayer data"...it loading for like 5 min. then says..."lost connection"....buuuut..if i chose any other FSX plane it works just fine...any suggestions???