Wireless Router help.

I have a Netgear WNR2000v3. It disconnects from everything wireless (laptop, phones, and PS3) every 4 to 6 hours and needs to be reset, but it stays connected to my XBOX (which is wired). I had a lower grade Netgear router and it never disconnected that often (maybe once every 3 to 5 days), and I had to switch because after 2 years it died. Any kind of advice would be much appreciated (like any type of settings suggestions, or anything that can be changed in the options, etc...).

Additional info: I use it as a gateway wireless device for my cable modem if that helps.