Thanks Bruce, It was the instance manager - I used the exeCalculate( ) in another part of the form, and tested it with an app.alert to ensure the rows were then counting the number of instances correctly to perform the calculation properly. 

I am using the below code to sum a dynamic table.  Each time I add a second "Table1.Row1" row, and select the value that would render countU ==0 true, the Livecycle form will not re-calcuate the query correctly unless I re-select the first row "Table1.Row1" countU value.  In other words, the dynamic...