DV Hardware today published an article called: 10.5 Tips to fix problems with wireless routers.

Reset your router - Some times after many changes and many restarts your routers configuration files can get messed up. Even after you made many changes via your routers web interface they won't stick. So you might need to reset you router by taking a paper clip and pressing the button in back of the router for about thirty seconds. This will reset it and give you a fresh start..

WiFi Router Troubling Shooting Guide