This happens after a few minutes of playing MW2 and it last for a little bit after I finish. it can also go back to normal during sessions then weird again.
Windows 7 64-Bit
Core i7 @ 4GHZ
GA X58A-UD3R
XFX ATI HD Radeon 5870
Patriot Viper 6GB 1600MHZ Ram
Xonar D1 PCI 7.1
Ever since I installed the sound card. Makes everything, whole system, just lag, not hugely, but frequently.