[dighsx]

Well some good news and bad news Chris, the bad news it I was able to run all your files and not have an offset problem. Also I could open both of Tony's files. (I guess that's the good news too)

Here are some random thoughts on what you might try. When saving your toolpaths in VCW use the gcode inch (or metric if you use metric) postp. That's the one I always use for Mach2 and Mach3. I know there is a Mach postp but for some reason I've never used it. But try the gcode one and see if you get the problem.

Also if you're changing tools in the middle of the job (and I'm assuming you don't have an auto tool changer) You're going to have to rezero the job in the Z axis at the least. When you run one of the files you posted and it finishes cutting where does the machine go? Back to zero X zero Y and maybe Z is above the work some?

Also do you have the latest ver of Mach3? Have you tried to see if you have this problem using Mach2?

Also did you say you set an offset in VCW? If true any reason why?

My gut tells me you're having one of two problems. One you’re using the wrong/old postp in VCW. Two you're not zeroing out after tool changes. Or there you both 1 and 2 are your problems.