Posted 22 January 2009 - 07:26 PM
It's possible for someone on your network to have the same ip as you. It doesn't necessarily mean that you've been hacked, but that's also a possibility.
Check what sreez mentioned. If someone has the same MAC address as you, then I would say there is an intruder, since MAC addresses are specific to the network card and nobody else can have the same one as you. IP's on the other hand are different. They are assigned by the router (usually) and can conflict. For instance, if your ip is set to static (you set your ip yourself) and some other computer's ip is dynamic (set by router) then there could potentially be conflicts.
Sometimes this happens. If it keeps happening over and over, then set some static ips. If it doesn't, then your router has fixed it.
As a side note, it would be smart to change your router's encryption protocol to WPA or WPA-2 preferably. WEP is actually really easy to crack using easily accessible tools on the internet. If possible, I'd definitely change it to WPA-2.