some type of malware infestation. Try running the various scans offered here:
Additionally a firmware update of the router couldn't hurt.
I have 2 computers and a PS2 in my house. My wifes computer and the PS2 are hooked up wirelessly. Recently the PS2 and my wifes comp have been losing interet connections. She constantly has to restart her computer and I keep having to unplug and replug the power to the router. I have tried obtaining IP automatically and also assinging IP addresses. I'm using windows XP. Any help would be greaty appreciated as my buddy has been helping me but to no avail.