After upgrading to 4.0 (system & voicemail PRO) every once in a while I will receive a notice from either a user or customer that says that when they attempt to dial an extension (usually from our main auto-attendant) it will just ring and ring and ring!!! The phone is covered by voicemail. The problem can be fixed by either rebooting the system, or by restarting the VM Pro service, or (this is the best one yet!! - by unplugging the phone from the system and plugging the phone back into the system!!) There doesn't seem to be any rhyme or reason for this behavior and I have tested many different scenarios. Once minute an extension is fine (no programming or modifications were made during this time) and then the next minute the VM is not answering for the extension (replugging the phone immediately takes care of the issue - and is the simplest solution). Has anyone experience this? This is definitely not a programming issue and I am convinced that it has the look/feel of a bug somewhere. It has happened to different phones and at different times (i.e. one phone will not be working but all the other are) Any ideas or has anyone else experienced this??