How often do you reset the router? Just by the sounds of it, probably not often. Home routers tend to require an occasional "soft reset" (remove power for a while or tap the reset button in the back) to keep functioning well. If you don't do that, they're likely to pull some very strange things, generally requiring a "hard reset" (hold down the reset button until the lights do something fancy; typically five seconds). That will restore the router to factory settings and fix whatever went haywire, so long as the hardware is okay.
