Problems with a wireless NIC.

Ok, here's the deal. I have a wireless network card that is attempting to connect to another wireless network (which is not mine). I've tried everything I can think of to keep it from doing so.

The computer is running WinXP SP2, the router it should stay connected to is a Linksys BEFW11S4 and the the NIC is a Linksys WMP54G.

They router is WEP enabled and it doesn't broadcast the SSID (and I've even gone as far as to disable the broadcasting of the SSID on the other person's wireless router while I was connected to their network, although I have no clue who they are). Any ideas as to why it would keep connecting to the other network whenever it detects it?

Ditch SP2 and see what happens. I've run into major headaches after loading it. Don't have a link but MS has admitted there are issues despite the hoopla...

Problem was resolved. Just had to disable Windows from managing the wireless networks.