I had the same problem noted here. Signed up with Comcast for speed and lower cost and got both along with the worst service on the planet. Fortuanatley I was able to get it to work after three techs (two of which had trouble speaking english) at comcast failed to help me. I reset the modem via the reset button in the back, and via the techs at comcast and via removing the battery, and via removing the power cord and battery for 15 minutes all failed to work. Finally I went into the airport utility (applications-Utilities-airport---on a mac and start-all programs-airport on a PC. I reset the airport to factory settings then then entered new settings (set to WPA and DCHP when asked) and then reset the modem again and it worked. Hope it works for you.