Brendan - I have given that some thought too, but since it responds to functions I am discounting it for now... I am thinking of trying to set up a double-header with the Sd70 and Es44 just for kicks and see if the Es44 responds!
However I am leaning towards believeing my Lenz Set is either incompatible or under powered and may need a booster as Rusty has suggested.... I retried the Sd70 this afternoon and found it more inconsistent in movement reponse then I first noticed! Also the fact that neither of the ALCOs react to DCC at all seems to point that direction...
Laurin