duplicate ip

I have just downloaded and installed Windows Vista on my laptop, and it looked fine, but when i tried to get it on to my network, boy did i run into problems!
When my netcards gets configured, both of them reports duplicate IP on the network, even if they get the IP from a DHCP server, how is that possible?
My Zyxel P-334WT ADSL router is my DHCP server, and in the computer i have a Realtek and Ralink BT2500 netcard and both of them fails.
Please help!
Kind regards Flemming Madsen

I have just installed Windows Vista on my portable, but when i try to get it on the my network, thats hwne the fun begins. Both my netcards (a Realtek cable and a Ralink BT2500 Wireless) reports duplicate IP on the network.
I have a Zyxel P-334WT ADSL router that serves as the DHCP server, how is it possible to have duplicate IP with a DHCP server?
I have 3 other computers running Windows XP an they have noproblems. before I put Vista on to the portable it too ran on the network with no problems.
Please help!
Kind regards Flemming Madsen