Just tried on my lathe and the feed per rev does alter and it is well screwed in that if you feed from X low to X high it is fast and the other way it is excruciatingly slow.
Now where does the problem lie? I had issues a while back with CSS and I asked around at the one or two that were using it with the PP and they said it worked fine, in later versions of the SS plugin I thought it was sorted but have only used it a couple of times and I was thinking it correct but obviously its not.
So as I said, where is the problem, SS or Mach?
Does anyone have a lathe on the PP that could test? I am SS, you are and also I think Daniel is.
Either way I think it will just have to be lived with for now or use the F/Min as Daniel has said, tested here and I get the same results as Daniel. Brian is going to be looking at Turn but when I dont know and I certainly wouldnt be holding my breath and Greg seems to be up to his ears as well so not looking like he will be having a look at it any time soon, sometimes its a bitch to be in a minority

Hood