I always thought that the 82A and 82B connecting blocks for the 4A Speakerphone were interchangeable. Not so. The 82Bs work fine on single line and 6 button sets, but I can't get the 82A to work. Can't find any specific reference in the BSPs I've checked. Anyone have an idea why or what I would need to make it work? Or better yet, have any spare 82Bs? Appreciate the help - haven't run into this before!