At my club, we have a Lenz DCC unit, and this sort of stopping...starting thing happens. Lenz helped develop the Bachmann DCC unit.... Periodically when thei happens with the Lenz, there is a procedure to do a 'system reset' where you set the controlloer to address 0, press the F4 button 25 times (watch for the power light to blink at around 19 or 20 times), and remove the power from the unit. Turn it back on, and the problem disappears until a few people enter multi unit consists and the like and forget to delete them. I am not familiar with the bachmann unit, and this might be just and educated guess. Hope it helps...