Check the power supply on the router. Not so much with the WRT series, but with the newer Linksys I check the power supply voltage first, then start troubleshooting. With an intermittent or drooping power supply, you can have issues that don't make any sense and you'll spin wheels for days, re-booting this 'n that trying to figure out how things are mis-configured. If I know that there is a Linksys router, I'll make sure that I have a power supply with me on a service call.