Well, I finally realized that the tool was taking my summaryField and was increasing it by a factor of 6. Of course, I have no idea why, but as a quick fix I took the final line of code, and divided the summaryValue by 6. Now it's reporting the correct number!
var msg:String = chartLabel + " [" + featureSet.features.length + " " + entitiesLabel + "]: " + numFormatter.format(summaryValue/6)
This tool is great!
Doug