Bad pings! The pongs aren't great either..

I've got the comcast 6mbit deal. My roommates, and I get expected good download speeds. However when I try to play online games my pings are terrible, ranging from 250-900's. I get dropped from games like battlefield 2 all the time. I used to play wow, and my connection was always in the red/yellow.

This problem doesn't occur for my roommates when I try the games on their machine, so can I rule out our router?

it's a linksys wire/wireless cable router. I'm using onboard lan on a nvidia
nforce 2 400 ultra. is my board just too old? would a new lan card help? might I have some hidden firewall?

You input is VERY appreciated!