M301 multiple hot end temperature control

[Veenoh]

I'm finally starting to get some decent prints with my M301 using PLA, even starting to be able to switch colors. While tweaking the temperature settings in slic3r, to change the first layer temperature and then printing with the 3rd extruder, I noticed that the temperature did not change for the second layer and I don't think the first layer was controlled either. It was set to whatever I selected before the print started. I think only the first extruder's hot end is being controlled so when I selected the 3rd one, the temperature didn't change. All 3 thermistor temperature's are mapped to the 1st extruder's connection but not the control.

Any thoughts on how to make this work?

--Dave