What wireless modes are you using?
Try single mode G or mixed G and N?
What security mode are you using? Preferred security is WPA-Personal. WPA2/Auto TPIK and AES.
What wireless devices do you have connected?
Any cordless house phones?
Any other WiFi routers in the area? Use InSSIDer
to find out.
Turn off Short GI and Extra Wireless Protection if you have it. Under Advanced/Advanced Wireless.
Turn off all anti virus and firewall programs on PC while testing. 3rd party firewalls are not generally needed when using routers as they are effective on blocking malicious inbound traffic.
Turn off all devices accept for one wired PC while testing.
I am having this problem also. If you reset the router or save changes it will start to work then over time the wireless side will not work anymore. Like i had yesterday I was on and my wife was on in the am than, I left for work half way thru the day she was not able to connect anymore it gives you the device is out of reach. Then I got home in the pm and it was working again with out resting or saving changes. You will have the 2.4GHz light on the router and you will see it with your device but you cannot log on. I dont have any security on and it is still doing it. I am running hardware version: A2 and Firmware : 1.25NA with a Win 7 64 bit hardwired computer