Forgot to mention, it also seems to repeat the line number. I've copied a segment from the progam below:-
N10 X-126. Y44.9988 N10 G1 Z0. F1000
N12 G0 Z2.
N14 X-126. Y14.9996 N14 G1 Z0. F1000
N16 G0 Z2.
As you can see, N10 and N14 are repeated in the middle of the line. I should imagine the Hurco would see this as illegal.