How many users are sharing the wireless connection on this AP? As your bandwidth is shared amog the simultaneous users connected to the same AP, you may face slowly connections as you mentioned. In the other hand, maybe the AP is receiveing some kind of interference from different sources than others access points, what is causing this strange behavior. I've seen similar behavior before, an access point was installed near to a conditioning air machine, what was causing electrical induction on the UTP cable.
HTH
This message was edited by Fred_Mancen on 11-19-09 @ 6:45 AM