i'm on a network at my house with a PC connected to a linksys wireles router. its been working fine for about four years now. today, a couple of hours ago, the signal slowly became weaker and weaker until finally it gave out completely. now my computer (powermac) will randomly pick up the signal again every once in a while for like 15-20 seconds. what could be wrong? router giving out? something to do with the network configuration? what gives?