HBoxPlotModelMapper not plotting anything or calling functions in model

I have a BoxPlotSeries backed by a QAbstractTableModel.  I am able to render the data using a VBoxPlotModelMapper but not an HBoxPlotModelMapper.  When using the HBoxPlotModelMapper, none of my functions inside my QAbstractTableModel class get called (like data).  I have attached a zip with an example demonstrating this problem.

Screenshot showing VBoxPlotModelMapper on the left and HBoxPlotModelMapper on the right.  Notice, how there are no box and whiskers like there are on the left.  I expect there to be 5 box and whiskers similar (but not exact) to the ones on the left.