When i try to log in extension 3506 it will log in and look like everything is normal but when you press any key on the phone you get an error tone. This happens no matter where i try to log the phone in. I have tried removing and recreating the extension (including VM) both by duplicating a working extension and creating from scratch, replaced cabling, replaced phone, ran find and remove from SA. This is on a 9640 phone. I added the extension as a bridged appearance on another line and it works. Server is running release: S8800-015-02.1.016.4. I'm at a loss and would appreciate any other suggestions.