Does it have a USB port on it? Some have so you can flash it that way. I fixed my old router for a few weeks by taking it apart and shorting to the CMOS (it told me how to to this on a website) but it only cured the problem for a few weeks and then the DNS tables would go funny every 30 minutes again.

I have replaced it now.

I used to have a Linksys hub but it was just a dumb thing with a simple amplifier built into it so there was nothing that could go wrong as it had no packet switching.