Steam Servers Huge Lag problem.


I recently got my multiplayer c++ game working over the steam servers. The servers are hosted using a Client/Host structure. I use the default create/find/join nodes to use the steam servers. Now when we played my game over the LAN everything was working fine and there was no lag at all. But when we play over steamservers the game begins to lag out. Note that nobody had a ping or 11 to 15ms. I created a simple demo wich was a new character on a empty map with no rpc getting called and it still lagged out. So i think this is a error with the steamservers. Does anyone else have the same problem and maybe know how to fix it ?