I'm fighting through a similar issue right now.
Ver 4.1 with embedded.
Multiple users share a single phone. A user has a DID number assigned to a key on a phone along with a message key.
The message key is lit. Pressing it brings you into the "please enter your password" of the users vm.
There are no messages. Leaving a message for the user and deleting it does not resolve. Dialing <feat On>+<ext> and then <feat off>+<extn> doesn't resolve.
Can't remove the key from the phone because "Line is in use".
I set a different users phone up as a Voice mail port, put the phone in each hunt group and then attempted to deactivate the light. No good.
I can delete the MSG key by adding a Superkey to the phone and deleting it at the set itself, but if I add it back so the user has a msg key then it re-activates.
I'd like to turn the DID key into a real set and then try it, but.... don't have any licenses to work with. No IP set or analog lines.
This has been a real pain.
I'd like to see Mitel and a command line to deactivate msg keys.
And... While I'm on that subject, I'd really like to see Mitel add the ability to, from the command line, activate/deactivate any feature on any phone that the user could do at the set.
I work from our remote center. This would save a lot of grief since I get a lot of tickets because a user was screwing with their phone.
Ralph