Network Printer and Share Drives Access

We have Windows NT/2000 servers on our network. The Windows NT servers are the primary domain controllers. Windows 2000 servers do not have activie directory installed and are not domain controllers. Problem:

When the Microsoft Security Rolluppatch or the Microsoft Windows 2000 SP3 is installed to a PC, the user cannot access (access denied) the printers or the share drives (all of which are on Windows 2000 servers). They can access printers or share drives if they are on Windows NT servers. However, the administrator can access the printers and share drives if logged in on the PC. Not sure if the mixed (Windows NT/2000 servers) environmnet is causing this problem. I guess it might be better to go with all Windows 2000 servers instead (this would take a little time to implement).