The only thing I can think of, is did you have to alter the arc settings in the mill profile, and they've some how been carried over the turn profile?

Failing that, as Nick says, Mach 3 forum is your best bet. I've never used CAM on my lathe, as I either hand code things, or glue together the wizard outputs. Plus I've not used Mach on the lathe for a few years now.