WIN2003 SBS, XP Pro Clients can log in but not open folders

WIN2003 SBS Server
Clients running XP Pro
Router Linksys WRT54G
– Firewall is off
– DHCP server is disabled

Clients can log in to the server and view the file tree but cannot open any folder on the server. I have check permissions on the folder and it is wide open.

** The clients were able to open the folders once but after a reboot of the client they cannot. I have shut down all services on the client except for the OS services. WIN Firewall is off. Wireless card disabled. Using wired NIC.