Since last Thursday, I've been experiencing really bad lag on my Xbox 360 and my son has had the same problem with PC gaming. I reset the modem and router and still had the same problem. Comcast came out today and connected my Xbox directly to the modem. There was zero lag, so he told me my router was bad. I went out and bought a Linksys E2500, hooked it up, and still have the bad lag on the Xbox and PC. Does anyone know what the problem could be?

*Update* I tried going directly to the modem again, and now there is lag with that connection too.