I have a KeyVoice voicemail system on a Nortel DR5. Occasionally messages are getting deleted when they aren’t supposed to. According to the digit grabber the voicemail is "hearing" a 4 (the delete code). Where is this digit 4 coming from. Are there DTMF receivers that could be going bad? If so, where are they? Could the VMIs be the culprit? So far the is no relation in the occurrences different extensions, different vm ports, different VMIs, different users. Any help would be appreciated.