Me and my friend have just tried to play online. Normally, offline, his FPS is miles better than mine. Just now, he had 12 FPS on our game and I had a steady 30 FPS... Any reasons for this?

Thanks,
Marc

Have alook at other posts on this under Technical - you will find something there to assist

I've gone through almost every page and I can't find anything I've searched too!

I'm afraid we really cant give you much advice without knowing some of the circumstances, etc. etc.

Was he the host, or you?
What spec are your machines?
How many other players, and AI were there?
How were you both connected?

We tried it with him as the host and me as the host. His PC is better spec than mine, because he gets 80 FPS in single player. No other players, it was a private server. We were both connected on the same service from the same provider.

Quote from Marc Ainley :

We tried it with him as the host and me as the host. His PC is better spec than mine, because he gets 80 FPS in single player. No other players, it was a private server. We were both connected on the same service from the same provider.

Then it make sense he is getting better FPS.
Please post your PC specifications so we can try to help you somehow.