I just recently performed a migration from Server 2003 SBS to 2008 Standard. The 2003 server was the PDC- All 5 FSMO roles transferred cleanly, and dcpromo went perfectly on both servers. The old 2003 server is still attached to the network, and suddenly in the afternoon the network slowed to a crawl... My customer shut off the old server and network speeds resumed to normal. DHCP and DNS server services have been shut off on the 2003 server. All DNS entries on the new server have been verified and are good. Any thoughts??