I couldn't play Call of Duty 4 online with 7600gt so I upgraded it to 8600gt. I still can't play online becaue it is so slow. What could cause this problem? 8600gt is good enough for CoD4 multiplayer right? I have Verizon dsl and my pc is running duo core 2.4 with 2gb memeory and 600watt of power with 8600gt nvidia. Is it my dsl service?