When being installed, Windows 2003 SP1 RC populates the registry key CSDVersion at:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion with the value in the format not recognized by QMM console.
Therefore, the QMM console when checking the SP version considers the server not to meet software requirements and does not allow the agents to be installed on the server.
To work around the issue, the SP version should be cleared from the CSDVersion key. After agents have been successfully installed, the registry key may be restored.
However, restoring the key will prevent target server refreshing, therefore, if refresh is required, the key value should be cleared again before refreshing the server.