Hello and misbehavin' TRAK DPM

[Cullen]

Hello to the group. I am a home shop (retired) machinist who finally got a cnc machine and am having some difficulties making it work consistently like I want. The machine is a TRAK DPM using AGE3 operating system. I drew up the project using CAMBAM and generated the G-code and loaded it into the machine. TRAK rewrites its own version of "events" sequences to run through. The problem I am experiencing is that every once in a while I get an error message that says the z-axis is out of range. The axis is however (by what I can see) is within the limits that I have set. The back-off was set to +5mm and the lower limit was set to -50mm. The program was working in the range of (0 to -12mm) when the error message shuts things down. Any ideas as to what would be causing this? The TRAK does not like to use "tabs" to hold a part that is being profiled out of a sheet of material. It claims that the mills are parallel and shuts down. I am new to both cnc work and this machine, so if anyone has experience with this machine, I would like to get some insight from you. Cheers, Cullen