Z-axis difference between Mac and PC control

-associated files are in this Dropbox folder: https://www.dropbox.com/sh/wtgr8jtv5jm50wd/AACfmgCNNV-g6tdnw-PuzO95a?dl=0

I am often using an Ultrabook to control my SO3, but noticed that the file I am linking “0125Omniboard…” started cutting way too deep and gave me a lost serial connection shortly after starting the first cut. So I switched to my Mac laptop and the same file gave me the correct cutting depth and finished the project.

I am using 1/8" hardboard. The PC is giving me a full cut with one pass. The video in Dropbox shows that full cut just past when the bit turns the corner and you can clearly see the base material. The Mac takes four passes to make a slightly less total depth, which is what the file is designed to do. The “MacStill.jpg” shows that there is less depth in that first cut.

Using Carbide Motion 3.0.356 on both machines.