If it's happening on BOTH wireless & ethernet, I suspect the router. There was one model of Linksys 54G routers that I were known to be problematic. What I would suggest is to turn off the wireless access, unplug the router for a minute, plug it back in and see what happens. If the issue is still there, then I would return/ exchange the router or buy a new one. Dlink or Linksys are my preferred brands. DLink seems to be a little slower that Linksys when it comes to the wireless side, but not terribly. Linksys seems to be a little more robust on the wireless side.