Windows 2000 Pro/W2k server/DHCP

I have a Windows 2000 server running DHCP and AD in native mode. I have Win98 clients and W2K Pro clients as well. I have the IP address of the server as the primary DNS server in my DHCP scope. The Win98 clients have no DHCP problems, but the Windows 2000 Pro clients have problems renewing the lease on their IP address at times. They don’t obtain a lease. If I go to the server and stop/restart the DHCP server service, the W2K clients can then receive a IP address. I’ve scanned MS site, usenet, etc. Can’t find any help anywhere. Server is running SP1.

Thanks alot.

Brett