I have been using Mastercam for 20 years I know my tool paths are not the problem its the way Mach4 is interpenetrating it. All my  Arc. are makings full circles if I change the Absolute incremental arc setting It either cuts in wrong or cut away from the part .Not much liking this new software. Anyone have similar tool path problems with Arcs in the Lathe? What do I need to do to fix this ?

Mill has tool path problems as well. It makes sense that both apps would have this issue though. Have reported it some time ago. Get the "Ill report it to the developers" response. I'm sure nothing is being done as they didn't even ask for the file that caused the problem.