Oh... thought that threading issue with the CSMIO had been resolved.
Mentioned it to Greg a few times in the past, but as I recall he didn't know how it was different from the SS. He said he was pursuing the original Mach's behaviour and thought this was the normal behaviour it. On the small lathe I too have the habit of turning the spindle off prior to Stop, but sometimes I forget which is not a big deal - it's not nice as you say. However, with this machine, it is much more than being merely not nice with a chuck weighing more that 70kg.
As a workaround I could probably send a signal from Mach upon a Stop (or Reset) hit, to the Servo Emergency Stop input. Somehow, hoped you might had a more elegant solution for this after years of use
Anyway, will talk to Greg again, and unless he can fix it real soon, will have to switch to CSMIO.
Have you switched to Mach4 on any of your machines, by the way?