Estop in Mach3, strange behavior

[firefight100]

Have tried several versions of Mach3 and they all act the same.
For no known reason or time frame, I will get an Estop function in Mach.  Hitting reset will not cancel it.  I have to go in to pins and ports and change the active high flag to the opposite of what it is.  Then the next time this happens, I will again have to change the active high flag.  There is no rhyme or reason for this.  It may work normally for a week and it may happen twice in one day.
Not a game stopper but it is pretty annoying.
Anyone have an idea to what is happening?

[romaxxcnc]

Settings in Mach3 changing for no reason is usually an indicator of the CPU in your computer is not stable - corrupting the XML. Try a different PC.

-Ron

[firefight100]

I found the problem to be a flaky connection in the parallel cable at the WD1 front panel. Just barely touch it and it would cause the estop to set.