Outer cut cutting too deep

Pleas could you help.
I have just finished a build to my own design, or at least I drew my own plans but followed a tried and tested design.
Anyway less of that, here's my problem, whenever I do a clearance or levelling pass when it does the final pass around the outside it cuts about .2mm lower than the rest of the level, it does this regardless of whether the toolpath is offset or raster.
I am using Vectric Aspire to generate the toolpaths and Mach 3 to control the cnc through a TB6560 controller.
One other thing I am having to work that machine in inches because regardless of what I do I can not get it to work in millimetres.
If I save the same toolpaths in metric and run them on my little chinese 6040 then they work perfectly.
Anybody got any idea's that may help me.

Zip and attach a sample of code where the part has both the Inch/mm issue and the depth issue.
Inch/mm is most likely you PP not setting units. G20/G21