Please HELP!! Network connection interupted

Hey Guys,

I was wondering if someone out there has any advice with my network problem. Here's the problem When playing games online COD4 or WIC every few minutes network interuption comes on during online game play. This has been going on now for 2 weeks. I have already update the software on the router, changed the cables, reset the router and replaced it but for some reason it still pops up. My wife has a mac laptop and she can surf the web without any problems using the wireless. It only happens to my computer which is hooked up wired. I even updated my internal network software and still no changes. Any advice?

Here's my specs:
Intel 957xbx
2 gigs of ddr 2 800
HD 4850 in crossfire
corsairs 620HX pwoer supply
Netgear wireless g router
and linksys cable modem

Thanks