the software upgrade did it. I bought a different 1610-1 board which had software version 101 (from 2001) .... my machine got a decade's worth of thinking in control software crammed in. totally great. now if someone would just give us all the codes / procedure to unlock advanced feed forward.
I can DNC macro code just fine now and that means I can use my probe systems effectively. change fixture offsets, measure tool diameters, check for broken tools - the lot.
I did notice that over DNC it doesn't do the PRINT / INPUT commands in a great way - the messages dont really get displayed, but the control does wait for input and you have to press enter to keep going.
but, no more error messages, and no more in-action.
ran the probing cycles - used all the #V, #FX, and R statements that I wanted to, all went off without a hitch. checked out the fixture offsets after and they were updated by 0.0001" or so each time I ran the program over DNC.