barLabels in a stacked HorizontalBarChart()

Hello,

I am working on a stacked HorizontalBarChart.
My data series look like this:

    data = [(1,1,1,2,1,1,5,1,2,1,3),
                (0,1,0,2,1,0,1,0,1,0,2) ]

Since the second serie includes the value  '0' the barLabels overwrite
eachother in the chart. Is it possible to not show the '0' values or
better, is it possible to show the total of the two series as a barLabel ?

Thanks in advance,
Helga