I don't own a butt set. I do however have a Walgreens phone I picked up for 5 bucks. On that phone when I call it and pick it up, I hear digits being dialed. Just 4 digits and then the call is established. I think you might be right. The digits may be being dialed after the call is connected. It's hard to say with certainty. I did not request the digits from the CO. Before I call XO and have them kill the digits, any ideas on how I can get a modem to ignore them?