I have a six-year old Linksys WRT54GL router, but twice this evening I lost connection with it because it reset all of its settings (SSID back to "linksys", network went insecure, port forwarding table wiped out, admin username/password reset, etc) to the factory defaults. I set it all back up after the first time, hoping it wouldn't do it again, but a few hours later (four or five hours) it did it again.

So obviously I here to ask why this is might be happening. Both times it did this while I was connected to it on multiple machines and I know nobody physically touched the router. The power didn't go out or anything, but I can't say for certain whether or not it rebooted itself when it happened. Is it just doing this because the router is really old? Or is it likely someone (or a virus?) is hacking in and resetting it all somehow? I don't think that's likely, but you never know, I guess.

The router's set up with a WEP code, and the username and password are changed from the defaults, and I don't thhhhink any of the computers on the network had the username/password saved, but mine might've. I tend to check password-saving checkboxes instinctively...

This router doesn't cause us nearly as much grief as our ISP, but the router says its firmware is six years old, and that's probably correct for the hardware, too, so maybe the router's just too old and needs replacing. Or maybe there's a virus out there targetting people on Linksys routers, resetting their routers to the factory settings instead of doing cooler, more productive things like stealing personal information.