I have a problem with one of user's 7975 phones. About half of the external calls that are coming into it are disconnecting as soon as the call is picked up. This does not happen with internal calls or other users. I have reprogrammed their extension to another phone, but the problem continues and could actually be worse. Has anyone run into this issue? If it was happening to all my users, I could understand it a bit better, but it is just a single person with the problem.