Windows Server 2003 domain problem

In my office we have all of our computers (running win xp sp 2) working under a domain network (no roaming profiles), the domain server is running win2003 server. Whenever I join a computer to the domain, I am able to access all the shares in the network, but if I want to set up in any worstation user restrictions I’m only able to see the local accounts for the workstation and I cant see the domain users to either allow or block them from accessing local shares on a worstation. File and printer sharing works without a problem, but I cannot specify the restrictions or permissions for domain users.
Any ideas?. I appreciate the help