Description of User CALs (Client Access Licenses) and Device CALs in Windows 2003The main point from this article is that a Terminal Services Licensing Server can only supply Device CALs or User CALs, not both, and the CAL type being used must be set in the Terminal Services Configuration applet:

If not, the Terminal Services Licensing Server will issue temporary CALs which will appear as Temporary Licenses for Windows Server 2003 - Terminal Server Per Device CAL Token or Temporary Licenses for Windows Server 2003 - Terminal Server Per User CAL Token.