Re: Voicemail lamp on with no new or saved messages
When you go into Unity Administration, and look at the settings for that particular Subscriber, what does the MWI status show? (I believe it's in the Messages section) That should represent Unity's view of whether there are messages or not. In your situation, it should show "Off", since you have said there are no messages.
In the same location, there should be a button to synch up Unity's view of the MWI with the MWI. Click on that to see if it resolves your issue.
If not, here is a link to the MWI Troubleshooting Guide:
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.