Unrecognized Command: Ratio using the Intensity Correlation Analysis plugin

[John Alexander-7]

This was working fine last week.  When I run the Intensity Correlation
Analysis plug-in, I get an "Unrecognized Command: Ratio" error ...
I can't for the life of me figure out what is going on.

The frequency scatter plots are often half-filled and other odd things.
It only appears when I have either the Display Colour/Frequency Scatter
Plot option checked.