The status in CallManager is really the true status, so if it currently says Not Registered, then something is amiss. Can you post the config of the VG200 as well as the output of debug mgcp packets? Turn on the debug, and then restart the MGCP process on the router by typing in 'no mgcp' followed by 'mgcp' in configration mode.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.