PC generating multiple DHCP leases

I have a Dell Laptop running Windows 2000. It is obtaining its network address from a Netgear router/firewall. Whenever I restart this laptop, the firewall reserves 3 dhcp addresses, but the computer is only using one. I set it up for a static address in the tcp/ip properties and now I only get 2 dhcp addresses. Is there any other service on the computer that could be trying to register an address?