Dynamic ColumnSet rendering as 'overlaid' instead of 'stacked'

Question

Hi all...
I'm struggling to get a stacked column set working within a cartesian chart. The chart object and horizontal axis are defined statically within mxml code, and the column set, column series, vertical axis, and other vertical axes, axis renderers, and line/plot series components are all defined dynamically in actionscript.  I've seen several examples online, and I appear to be doing everything the same way, yet when I specify my ColumnSet object's type attribute to 'stacked' it renders all the column series data as overlaid instead of stacked.  I can specify 'clusterd' dynamically (leaving everything else the same) and it will re-render correctly as clustered, but I've tried several different 'workarounds' to try and force stacked to occur without any luck.
Has anyone else seen this sort of prolbem before?  I'm using Flex 3.5 and run inside Flash Player 10.
I've been struggling to get this working for several days now, so any help would be appreciated.
Here's a snippet of the MXML definitions:
                    <mx:CartesianChart id="myColumnChart"
                                    doubleClickEnabled="true"
                                    width="100%"
                                    height="100%"
                                    paddingTop="2"
                                    paddingRight="2"
                                    styleName="ColumnChart"
                                       showDataTips="true"
                                       dataTipFunction="dTips">
                        <mx:seriesFilters>
                            <mx:Array/>
                        </mx:seriesFilters>
                        <mx:horizontalAxis>
                            <CommonCtrlElem:EspDateTimeAxis autoAdjust="true" baseAtZero="false"
                                              displayLocalTime="false" 
                                              displayName="{myTSField}"
                                              dataUnits="{myTSPrecision}"
                                              labelUnits="{myLabelPrecision}"
                                              maximum="{maxHorAxisVal}"
                                              minimum="{minHorAxisVal}" 
                                              />
                        </mx:horizontalAxis>
                        <mx:horizontalAxisRenderers>
                            <mx:AxisRenderer axis="{myColumnChart.horizontalAxis}"
                                             cachePolicy="off" canDropLabels="false" canStagger="false"/>
                        </mx:horizontalAxisRenderers>
                       <!-- The series data for this chart will be
                              determined by the updateChart() function
                        -->
                    </mx:CartesianChart>
The overall chart 'series' is built as an Array object, with the first element being a ColumnSet containing an array of ColumnSeries elements as the ColumnSet object's 'series' element value.  Then there are other Plot/Line series elements appended to the top chart's 'series' array before it gets tied to the chart object as its new 'series' component value.
There is alot of other stuff going on within the actionscript, which is why I have just summarized the order of it above rather than include it.  As I mentioned previously, it works fine if I specify the ColumnSet's type attribute to 'clustered', so I know all the data is there and getting set up properly...it's just showing up as 'overlaid' instead of 'stacked' if I specify 'stacked.'
Thanks in advance,
JJ

Answer 1

I should add....
If I define my same components statically in mxml, the stacked chart renders fine.  It only appears to be a problem if the series is built dynamically.
Here's what the series component equivalent looks like in mxml (where it stacks just fine):
     <mx:series>
          <mx:Array>
               <mx:ColumnSet type="stacked">
                    <mx:series>
                         <mx:Array>
                              <mx:ColumnSeries .../>
                              <mx:ColumnSeries .../>
                              <mx:ColumnSeries .../>
                         </mx:Array>
                    </mx:series>
               </mx:ColumnSet>
               <mx:LineSeries ..../>
               <mx:LineSeries..../>
               <mx:PlotSeries.../>
          </mx:Array>
     </mx:series>
Thx,
JJ