title: Flex chart with multiple Y axis shows wrong horizontal origin
body: <p>I have created a flex chart with multiple Y axis. I want that it shows origin for one of the data series. It shows the line, but on the wrong plase.</p>
  
  <p>Maybe it is because I didn't tell to GridLines which axis use as a source? But, I am not sure if it is possible to do...</p>
  
  <p>Please help if you know how to show horizontal origin on a chart with multiple axis.</p>
  
  <p>Here is an examle which reproduses my problem.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
             xmlns:s="library://ns.adobe.com/flex/spark" 
             xmlns:mx="library://ns.adobe.com/flex/mx" 
             xmlns:local="*" 
             height="450" 
             width="500" xmlns:components="components.*" xmlns:charts="components.charts.*"&gt;
  &lt;s:layout&gt;
      &lt;s:BasicLayout/&gt;
  &lt;/s:layout&gt;
  
  &lt;fx:Declarations&gt;
      &lt;mx:ArrayCollection id="arrColl"&gt;
          &lt;mx:source&gt;
              &lt;fx:Array&gt;
                  &lt;fx:Object name="R Winn"    slg="445" avg="0.300" /&gt;
                  &lt;fx:Object name="P Feliz"   slg="418" avg="-0.253" /&gt;
                  &lt;fx:Object name="O Vizquel" slg="316" avg="0.246" /&gt;
                  &lt;fx:Object name="B Molina"  slg="433" avg="-0.276" /&gt;
                  &lt;fx:Object name="R Durham"  slg="343" avg="0.218" /&gt;
              &lt;/fx:Array&gt;
          &lt;/mx:source&gt;
      &lt;/mx:ArrayCollection&gt;       
  &lt;/fx:Declarations&gt;
  
  &lt;mx:ColumnChart 
               showDataTips="true"
               dataProvider="{arrColl}"
               width="100%"
               height="100%"&gt;
  
      &lt;mx:backgroundElements&gt;
          &lt;mx:GridLines id="grid1"
                        gridDirection="both"
                        horizontalShowOrigin="true"&gt;
              &lt;mx:horizontalOriginStroke&gt;
                  &lt;s:SolidColorStroke color="red" weight="3" alpha="1" /&gt; 
              &lt;/mx:horizontalOriginStroke&gt;
          &lt;/mx:GridLines&gt;
      &lt;/mx:backgroundElements&gt;
  
      &lt;mx:verticalAxisRenderers&gt;
          &lt;mx:AxisRenderer placement="left" axis="{axis1}" /&gt;
          &lt;mx:AxisRenderer placement="right" axis="{axis2}" /&gt;
      &lt;/mx:verticalAxisRenderers&gt;
  
      &lt;mx:horizontalAxis&gt;
          &lt;mx:CategoryAxis categoryField="name"/&gt;
      &lt;/mx:horizontalAxis&gt;
  
      &lt;mx:series&gt;
          &lt;mx:ColumnSeries yField="avg" xField="name"&gt;
              &lt;mx:verticalAxis&gt;
                  &lt;mx:LinearAxis id="axis1"/&gt;
              &lt;/mx:verticalAxis&gt;
          &lt;/mx:ColumnSeries&gt;
          &lt;mx:LineSeries yField="slg" xField="name"&gt;
              &lt;mx:verticalAxis&gt;
                  &lt;mx:LinearAxis id="axis2"/&gt;
              &lt;/mx:verticalAxis&gt;
          &lt;/mx:LineSeries&gt;
      &lt;/mx:series&gt;
  &lt;/mx:ColumnChart&gt;
  
  &lt;/s:Application&gt;
  </code></pre>