2 PS3's in same house playing COD5 online Problems

[Basshead]

I attempted to search but came up with nothing useful. A friend of mine has 2 PS3's connected in his home. One is hard wired and the other is connected wirelessly to his Verizon Fios issued wireless router. He and his bro-in-law attempted to play COD5 online from each PS3. Yes, they used two separate legit copies. While they could both join and play in separate matches, they could not be in the same team death match game. they are using different users on each PS3. Any advice or eplainations would be greatly appreciated.

Thanks, Tom