Slow network Access on 2003 Domain with Windows XP

Hey everybody, here is my problem.  I have basically 4 client computers and two Windows 2003 Servers.  All clients are running XP Pro with DHCP.  One server is configured as the domain controller running DNS, DHCP, and RIS.  The second server has a large hard drive for storage hence is my file server.  The server is trusted for delagation (for EFS).  This shares a printer and 2 file shares.  My problem from any client computer when I access my share mapped as a local drive it takes a good 15-25 seconds before it opens.  Now I know it is not network traffic becuase I have tried this with only one client, Not the NIC i've recently upgraded to gigabit.  I've also tried making an entry in a local host file pointing to my file server and still no luck.  This also happens when I map a drive from my domain controller.  And it happens on all clients.  I am completely stumped.  The network setup is like this.  I have a cable modem going to a router all clients point to my DNS server hosting the Active Directory and forwarders are enabled on my DNS server to the ISP's DNS.  My next step is to setup a test Windows 2000 client PC just for testing to see how it works.  If this still doesn't work I was going to place the servers in a different subnet than the clients to cut down on broadcast.  And if still no luck I'm going linux for File and Print sharing.

router:  192.168.0.1 (obviously static)
DC:  192.168.0.100 (static)
File/Server:  192.168.0.101 (Static)

Clients obtain DHCP:
IP:  192.168.0.104
Mask:  255.255.255.0
Gateway:  192.168.0.1
DNS:  192.168.0.100
Dns Suf.:  home.local