Losing series from chart when adding one

Question

I have a problem with adding a LineSeries to an existing chart.  It's a LineChart (but also tried bases of CartesianChart, CandlestickChart, ColumnChart, HLOCChart and AreaChart), which has a ColumnSeries (volume) and CandlestickSeries (stock prices).  When I add the LineSeries on the chart, the column series always disappears (and the right axis it's tied to loses the min/max range it had).  It doesn't seem to matter which order the series are in the list, always the ColumnSeries disappears.  Tried all the invalidateXxx methods on the chart, doesn't seem to matter.
        var sma1Series:LineSeries = new LineSeries();
        sma1Series.horizontalAxis = laCarta.timeAxis;
        sma1Series.verticalAxis = laCarta.leftAxis;
        sma1Series.xField = "time";
        sma1Series.yField = "sma";
        sma1Series.dataProvider = sma.data;
        sma1Series.displayName = symbol + " SMA (" + sma.period + ")";
        sma1Series.setStyle("lineStroke", styles.sma1Stroke);
        var series:Array = laCarta.series // volume and symbol series
        series.push(sma1Series);
        laCarta.series = series;
I can print out the series list after adding, they are all there.  Is there something I'm missing here? I can't find any reference to this issue anywhere.
Building with Flex 3.5, running in Flash player 10.

Answer 1

This is odd.  If I start with just the CandlestickSeries alone, then programatically add the volume (ColumnSeries) series, it adds fine.  If I then add the overlay LineSeries to the same set, it still kills the ColumnSeries, when doing it as a separate operation (e.g. button 1 adds ColumnSeries, button 2 adds LineSeries).
But if I add both ColumnSeries and LineSeries at the same time, even separately, it works.  For example, below works just fine, whether together == true or false.
public function addSeries(together:Boolean):void {
        var vr:AxisRenderer = createAxisRenderer(createAxis("Volume", 0);); // separate axis/renderer for volume
        var vc:ColumnSeries = createVolumeSeries(main.timeAxis, vr.axis);
        var sma1Series:LineSeries = createSMASeries(main.timeAxis, main.leftAxis);
        if(together) { // push them together
          main.series.unshift(vc); // put it first/bottom
           main.series.push(sma1Series);
           main.series = main.series;
           main.verticalAxisRenderers.push(vr); // add renderer
           main.verticalAxisRenderers = main.verticalAxisRenderers;
        } else { // add one, then the other
          main.series.unshift(vc); // put it first/bottom
           main.series = main.series;
           main.verticalAxisRenderers.push(vr); // add renderer
           main.verticalAxisRenderers = main.verticalAxisRenderers;
          main.series.push(sma1Series);
           main.series = main.series;