Trouble with wireless aspect of Cisco 871W router

Hello. I am having trouble with the wireless networks on my Cisco 871W router. I used the router config guide on this site, and that helped get the networks up and running. But at random points the router will drop all wireless connections on all devices (PC, phone, Wii, PS3, etc) The SSID will show up on my wireless NIC interfaces but it will not add any devices to the network nor will it forward any traffic. The devices connected directly to the router are not affected. This happens roughly every other to every third day. If I restart the router it works fine until it decides to dump everyone again. Anyone have any ideas?