Now, you can see why it takes so long between releases.   Without a debugger, to fix anything that goes wrong, it's a matter of elimination.   So in this case, since other maps work in on a coop server, it's now a matter of replacing one vehicle at a time with the atmosphere version to nail down which vehicles are causing crashes and then compare the code to try to figure out what the issue is.    Conquest mod is more forgiving of issues than Coop on a server.  So, just because it works on conquest doesn't mean it will work in coop multiplayer.   

If that failed, then I would port the vehicle to bF2 and use the debugger to help track it down.   The Atmosphere vehicles are clones of the space vehicles, and some may be missing some code or even an AItemplate.