What is going on? (connection problems)

I tried connecting to my friend's server last night. We both use Doomsday (latest version). Somehow, he can't get on my server when I start one.

The other way round works, but I don't see any demons move (coop), also I drop trhough the floor. Everything seems to freeze, but we can read eachother's messages. What the hell's going on?

By the way, when I start the server, everything moves (demons, I can shoot things). I just don't get it.

Anyone at all?

Maybe you have more luck on the Doomsday forum.

Sounds like your not using the same IWAD. You both need the same version to play together.

I copied his wad (plutonia). So we definitely have the same one. It's just not working.