Steve,
I'm not sure but aren't you using the mil tool change syntax (M6 T1) instead of the lathe syntax (M6 T01xx)? That may be causing a transverse to 0,0.
Just a thought.
Hugh Smith
% 'tcollet
N10 G21
N20 G90 F53.34 S700 M5
N30 G0 X20.0 Z40.0 ' Tool change position
N40 M6 T1 ' CHANGE TO TOOL # 1
N50 G43 H1
