Computer Management on Win XP Pro

We have some new workstations running WinXP Pro but I cannot connect to them using AD Users and Computers. I get an error message saying

“Computer \\computername.mydomain.com cannot be managed. The network path was not found.
Choose ‘Connect to another computer’ from the Action menu to manage a different computer.”

The Windows Firewall is off and Remote Desktop is turned on. The workstation is joined to the domain and can access shared resources on the network. What needs to be done to allow me to use Computer Management to connect to Win XP Pro workstations?