Hi everyone,
Purchased the game last night, and loving it! Well worth the wait. Runs like a charm on my PC for the main story as well as single player Deniable Ops, but I tried this evening to play the first level of the co-op story with my friend, and I had a horrible frame rate.
It wasn't 'lag', but just my frame rate dropped to what I would estimate around 12-15fps.

My specs are:
Core i5 750 @ 2.66GHz
4GB DDR3 Ram @ 2000MHz
Ati Radeon HD4890 (On the new 10.4 Catalyst drivers)

I stress the fact in everthing by myself, I run this game on High at 1680x1050 and its perfect, but I even reduced it to medium and I can barely play in co-op. Please note, he gets no slowdown at all. He is running a laptop with an ATI mobility HD4650, so I find it strange that I with the faster PC will get the slowdown.

We have tried inviting from my PC and his PC, so its not a hosting/internet speed issue as we both have fast ADSL connections.

Is anyone having a similar problem? Or know of a fix or an idea?

Thanks very much!
Hope you're all enjoying the game.

-James