charting.chart.nullvaluemode = gaps not working for Stacked Area charts

Hi

I have a timechart which plots a stacked area chart of multiple series. I want to omit the null values. I tried specifying charting.chart.nullvaluemode as gaps in my view.xml but it did not work. I cannot use usenull=f as I don't have a split-by field. Please suggest how I can achieve this behaviour with Stacked Area charts.

Thanks in Advance.