weird router problem, please help

Ok so here's the deal...

I go to school and live with 3 other guys, we have a 3mb cable connection through our isp which is then routed through a linksys router.

at the begining of first semester (sept 05) we had a wireless b linksys router, the router worked fine, all the time, rarely had to restart it. All of a sudden when we came back from winter break it has started acting up. I noticed it was very slow and would ping google.com for example and get times anywhere from 500ms-1000ms which is wayyy too high. (normally get 50-100ms)

I would then restart the router and the ping times would be fine , but then all of a sudden would shoot up again anywhere from 15-30 mins later. and repeat over and over.

thinking it was the router i bought a new one, a wireless G, and the same issue has been occuring. internal ping times on the router are fine, its just external. Im wondering if it could be one of my roommates machines has a virus that is clogging things up? any suggestions at ALL would help, and any other questions please ask

The router should have some basic logs you could look at. Also did someone discover BitTorrent over winter break? Lots of simultaneous connections will mess up home routers. Are these times taken over the wireless or wired into it. Maybe someone near you got a wireless router and now there is interference. You could try changing the channel your router is using.

I use mIRC myself but these ping problems happen even when im not running it. I will make 100% im not running it and then try from there, im gonna kick myself if thats the problem. Also all the ping times are over a wired connection, even the slow ones

also our neighbors have a wireless connection too but that hasnt been a problem, theyve had it for the same amount of time as us, and both of ours are secured

Anyone live next to you that might be tapping into your wifi? For the heck of it, change your WEP key, or use a higher encryption mode just for the heck of it.

i will try it, its really unlikely though just because there are really no other computer geeks besides me around our neighborhood, its a small neighborhood so i pretty much know everyone in the area

ok it is still doing it....i checked the logs and nothing is suspicious at all, i tried running mIRC right after i restarted the router and it did not slow down the speed...

i cant seem to find out what is slowing this down