I have a 2008 Domain controller where the printer ports look fine. On one of the Terminal Servers, running Windows 2000 Server the disappear when signing in as a Domain User, even Domain admin. However if you log in locally to the Server, they are there. Another Win2k Server in the same domain is fine. Any ideas?

Had a similar issue. Microsoft Premier support said to try the following The problem happened because somehow the Win7 client was trying to communicate with the printer server via the Asynchronous RPC protocol. This protocol is a new protocol only supported in Windows 2008 and Windows 2008 R2 printer serves. Because your printer server is Windows 2003, it does not support this Asynchronous RPC protocol so the Win7 client failed to communicate with it. There is a simple workaround for this problem, which is to add the following registry value and set its data to “6”. This will disallow the use of the Asynchronous RPC protocol on the client, so the client will always try to communicate with the normal RPC protocol and therefore the problem should not happen again. HKLM\Software\Policies\Microsoft\Windows NT\Printers\EnabledProtocols