Server 2003 ARRRRRGGGHHHH

I am upgrading an existing W2K domain to 2K3. The IP settings on the interfaces have gone crazy. Each time I set one to a static address, and then check it, the interface returns to obtain an address automatically. This has already corrupted the dcpromo on the second server I added (now down) as it changed the address on the fsmo roles holder during promotion.
Any thoughts?