OK. I used the Verify button and got the same results; i.e, the machine is maintaining positional accuracy. Interestingly enough, I ran the logo program again today. The program was written to cut the pattern twice to ensure a clean cut in wood. When I ran it this morning, the first path cut correctly and the second path--exactly the same code--cut incorrectly, truncating the horizontal lines in the C and E letters, like in the image I attached in my first post. I guess what I want to know is where to troubleshoot. Is the problem likely to be in my installation of Mach 3, in my controller, in my motor drivers or where? I can't understand why one axis (in this case the x) should cut too short given the code directions and yet still home correctly.