MP campaign not MP safe?

[nominesine 0]

I'm receiving some strange locality errors that only shows up in MP campaign mode. To make a long story short: It seems as if all players in a MP-campaign game is permanently treated as JIP players by the game engine. Hence missions that are working perfectly in regular MP screws up in Campaign mode for everyone except the acting host. Has anyone nticed the same? Can someone show me a workaround?