Adding probing to a sabre 1000.

OMI machine interface and OMP400 probe. Probe is set to OMP700 in acramatic. Otherwise wired 100% to the wiring diagram

G74 height calibration cycle works great
G78 bore locating cycle works great

I can't get G72 to run correctly. It starts but doesn't finish successfully - outcome depends on how I start the cycle.

probe is set as a probe in tools, rough length set and rough tip diameter set (6mm)

two different starting situations with different bad outcomes:

1. The help menu in RAP says to position the probe 'over' the exact center of the bore. Use G78 to center on bore - pull up 1 inch (arbitrary!) - press cycle start. the table will run to the right until the limit switch (basically the entire table) and then return a no-hit. (this seems wrong)

2. operating manual 3.0 pub 91203809--001 PDF says to position probe at the exact center inside the bore. again use G78 to center on bore. G72 cycle start. table runs right to bore edge. Over run the probe and report an unintended hit (40-55) (this setup seems right)

G72 & G78 both call for diameter - I'm using a calibrated ring gauge and using the same diameter for both operations.

What am I doing wrong?!