clients getting address from 2000 server, but not from DHCP

I am running 2000 advanced server, with RAS and DHCP. The problem is, something is answering DHCP requests other than the DHCP server. If I dissable the DHCP server, RAS, and DNS, client requests are still answered. Since I am using RAS, internet sharing is dissabled. I have two NICs, 10.10.1.1 and a 192.168.0.1. The DHCP server has two scopes set up to assing 10.10.1.100-10.10.1.254 and 192.168.0.100-192.168.0.254. It appears whatever else is answering requests is alternating. In other words, every other time you’ll get a 192.168.0.100-254, the other times you’ll get a 192.168.0.2-x. Any ideas what service may be doing this?