[ger21]

I'm not sure if Mach1/2 works like this (read the manual), but I think you need to add a lead in move for G41/G42, which wouldn't work for what you're trying to do. I'd need to see your code to see where you put the G41, but typically where your first G1 is after G0, the tool is not offset. It offsets from the first point to the second point. For instance, with a 1/2" D tool:

G1 X1 Y1 ( The center of the tool is at X1 Y1)
G41
G1 X2 Y1 ( The center of the tool is now at X2 Y 0.75)

Hope that makes sense (and I did it correctly)

Gerry