Steve,
I tried 5327 i am getting the same results,
I did use the m6 macro that came with the mach4 install this time, to eliminate the macro..
I ran a G0 X1 and a G31 Z-1 in the mdi and they worked fine, i hit the probe and motion stopped.
But the M6 T# does nothing, ran a G Code file again and got struck on the first M6 command.
I switched to the simulator mode and the m6 works ok there..
I am using a smoothstepper.
Do you think i have a setting incorrect?. it was working a few versions back and i don't think i changed anything
I do see you made a few changes to these version's i looked at the screenload script and that has changed a lot..
Let me know what you think
Gary