I'll give you something else to ponder. This morning, I took my two week old MTH SD70ACe to my LHS to have the decoder updated with new software. The update is supposed to make it play nice with DCC, allowng it to have speed tables, advanced conssting, and a total of 109 CVs that can be accessed and adjusted. They started at ten this morning,and by the time they closed at 5:30 this evening, it still wasn't done. It would get about halfway through the process, and crash. The LHS will call MTH Tuesday when they open at lunch time to find out what went wrong.
In the meantime, and the reason I bring this up, is currently the locomotive will function on straight DC power, BUT WILL DO ABSOLUTELY NOTHING on DCC. It has sounds and movement lie it should until trying DCC.
I hope this isn't what has happened to yours. I'll post back when we hear from MTH, and whether their solution fixed the problem.