If you do RMA it, I would RMA it to newegg rather than Linksys. You would have to go without a router for a week or so, but Newegg is very fast with returns.
First of all though, I would try reloading the firmware. Goto
http://www.linksys.com/download/ , choose your router and OS, and get the firmware. Reload the firmware, and see if that fixes anything.