Herb, I'm an old guy who can barely use a computer. So I can't say what the cause really is. For my system the TTS plays some sort of part in the problem. The guys on the Calkwalk forum say TTS works great and they have never heard reports of problems with any system. They think it is related to the way PG software implements bank changes or errors in bank change controllers. I don't know. I just hoped that the PG people would look at this while they are researching whatever situation you have brought to their attention with your bank change problems. I just want the pain to go away! Ha!