Read this it might help you troubleshoot:
Or, use the built-in Access Point to connect wireless devices to your network without running cables through the building. The Access Point built into the Gateway uses the very latest wireless networking technology, Wireless-N (draft 802.11n). By overlaying the signals of multiple radios, Wireless-N’s “Multiple In, Multiple Out” (MIMO) technology multiplies the effective data rate. Unlike ordinary wireless networking technologies that are confused by signal reflections, MIMO actually uses these reflections to increase the range and reduce “dead spots” in the wireless coverage area, maintaining the wireless connection much farther than standard Wireless-G.
With Wireless-N, the farther away you are, the more speed advantage you get. It works great with standard Wireless-G and -B equipment, but when both ends of the wireless link are Wireless-N, the Gateway can increase the throughput even more by using twice as much radio band, yielding speeds far faster than standard Wireless-G. But unlike other speed-enhanced technologies, Wireless-N can dynamically enable this double-speed mode for Wireless-N devices, while still connecting to other wireless devices at their respective fastest speeds. In congested areas, the “good neighbor” mode ensures that the Router checks for other wireless devices in the area before gobbling up the radio band.
