To transfer circular and polygonal area selections from images to the Statistics or Array Analyzer windows  Bersoft Image Measurement uses the current Background color, to differentiate the pixels inside the selection from those that are outside (the Background color is set in Tools Palette).

The background color is used to fill all pixels outside the selection. If some pixel inside the selection have the same color it is going to be considered as part of the background, not the selection.

That means that is very important setting as Background a color not present into the selection when measuring irregular or elliptical areas manually or when loading selections into the Statistics or Array Analyzer windows.