I had this problem as well. I have an Option 61C with CallPilot. I had to have my vendor load some patches into both the switch AND the voicemail to make it stop. It is a known problem by Nortel, and the patches did fix the problem. Problem is it costs money to have a vendor come in to load patches unless you are under a maintenance contract. If your under a contract, you should just have your vendor come in and load these patches to correct your problem. Best of luck. This one drove me crazy for a while.