I use a Level 1 WBR-3405TX Wireless AP Router at home and I use it both for LAN and Wireless with DHCP enabled.
I have configured the router to use a MAC-filter, i.e. "Only allow computers with MAC address listed below to access the network."
This works okey if I use Vista Ultimate or Linux (Ubuntu), BUT when I boot on my Win XP Pro partition - it takes TWO IP-addresses from the DHCP scope, one with a MAC-address that isn't in the "allowed" list!?!
I have scanned the XP installation for Spyware, Viruses and Rootkits, but it seems clean.
Does anyone have an idea of what this can be?
[EDIT]
I'll guess I have to do some serious network sniffing with Ethereal or another Network Analyzer.
[EDIT 2]
By the way - It's an almost new XP installation...








