Comment 1 for bug 919355

getShareSize ignores duplicate files. The file list size, I presume, includes duplicates. Therefore, the funtionality you are seeing is actually the intended behaviour.

There are two things that can be done; 1) mark this report as invalid (though, possibly adding information in the help file) or 2) make sure that duplicates are included in the size. Or, possibly, 3) have one label stating unique share size and one stating total share size.