Art,
I did a clean install of Mach 4 Build 1914 and Darwin2014-1-10.zip. I now notice a new behavior that wasn't happening with the previous versions that ran with Mach 4 build 1900 and prior. Using the same motor tuning settings, I'm now seeing an occasional "pop" in all three configured axis when I jog. I tried re-tuning the motors, but the problem got worse if I went above or below the original calculation. It's better at lower jogging speeds, but nearing 100% jog rate I start to see e-stops with messages saying that Darwin is too fast.
Any ideas?
-Freeman