First of all; what are you connecting to it (what kind of PC/network card)? With most models, if one device connects using wireless b or g, the entire signal switches back to that slow system. Plus, don't expect miracles from wireless N, the range is just not that good. Unless you have one of the very few dual band N routers, it's either ALL n, or no n.

The only decent way to get relaible wireless is with external range boosting antennas and a router with firmware capable of boosting the output signal.