I have a PS3 myselff, the only problem with Black Ops 1, 2 and MW3 is that you need to open your DMZ in the router. The DMZ function will make sure the ps3 can communicate with the other PS3's you are conecting to.
But i did the same for the PC but it didn't solve the problem so i will check this out. .
Thanks for this information, Just got the game myself and notied FPS issues, this def made things run smoother.