I purchased the DCC starter set with two engines and DCC controller.  I tested and ran both engines on my DC layout with no problems whatsoever.  Then I removed the DC power and connected the DCC power and removed my isolated districts for DC.  when I put the first engine on, I selected the default "3" and it worked perfectly.  I then placed the second engine on after removing the first only to have nothing happen.  It would not respond in any way.  I went through all of the programming steps and nothing, I even tried to run it in analog mode on pre-set 10, but still nothing. 

Santa is getting nervous, any help would be appreciated.