I went back and changed the Data Column call to the following:
=IF(LEN(Input!J7 ),Gen_Note(A7),"")

Then I made a Test column and put in
=If (Len(Input!J7),1,"")

The Test column always calculates a correct result. The Data Column still
requires that I move my cursor to the particlar cell, hit the left mouse key
twice, and hit return to calculate.

And I would expect to get a re-calc on loading the spreadsheet or using F9.

Thanks for your help,
Mac