would be my first guess. Linksys among other consumer oriented home networking products has shown a tendency to break down within a year or two of operation. Seek a warranty if such exists. In the mean time I would swap out a new one as price levels have made this a viable option.
I have a linkys wireless g/b router and have a few problems with it that just popped up. Only 2 of the 4 ethernet hookups are working and the wireless radio has shut itself off. I can't access the router to try and change anything, i've tried typing 192.168.0.1, 192.168.1.1, and my default gateway (found in run-cmd-ipconfig) into internet explorer it just doesnt load. I've also hit the reset button and unplugged it quite a few times but none of that has worked. Just had a big virus problem on one of my computers and that might be part of the problem. Neighbors couldve messed with it as well as the network wasn't secured. Any ideas on how i can fix this problem?