Did you try a different combination of buttons? I have set up a lot of these and never had that problem. You might want to have someone verify that both "b" and "1" are registering correctly at the controller. (possible broken traveller) Start from the beginning and have them watch to see numbers going up and b and 1 responding properly. You did say that DZ was working at all floors, correct? How fast is your car going? Is speed increasing as you get higher? I'm looking for anything abnormal. What part of the country are you in?