Recently I fitted an Athearn BB F7 A-B set with Digitrax decoders (DZ125's). They work fine most of the time but sometimes the lead unit won't start up on DCC (usually when the DCC unit is turned on for the first time of the day). If I switch the block to DC and give the locos enough power to just move them then shut down and switch the block back to DCC it then will start up and run just fine. Am I correct in assuming that this is because the decoder is having trouble determining whether or not the current it's getting is DC or DCC? I'm using a Bachmann DCC system so changing CV's is out at this time. Is there another way I can correct this or do I continue with the method I've been using? Starting the units separately isn't possible as the two units are hardwired together so they pick up power like a single sixteen wheel unit.