The problem is that I don’t get any graph displayed. I get the error “No data to display”

I have no problem generation/displaying Single series Charts graphs using the same setup !!
<?php
.
.
.
 $strXML = encodeDataURL("GraphData.php");
 echo renderChart("FusionCharts/MSColumn2D.swf", "", $strXML, "productSales", 400, 200, false, false);
.
?>
GraphData.php output:

- <chart debugMode="1" formatNumberScale="0" formatNumber="1" palette="2" showValues="1" bgcolor="F3f3f3" bgAlpha="100" useRoundEdges="0" legendBorderAlpha="1" divlinecolor="c5c5c5" showAlternateHGridColor="1" alternateHGridColor="f8f8f8" animation="1">
- <categories>
  <category name="vendorA" />
  <category name=" vendorB " />
  <category name=" vendorC." />
  <category name=" vendorD " />
  </categories>
- <dataset seriesName="Current Year">
  <set value="331" />
  <set value="189" />
  <set value="124" />
  <set value="11" />
  </dataset>
- <dataset seriesName="Previous Year">
  <set value="331" />
  <set value="189" />
  <set value="124" />
  <set value="11" />
  </dataset>
  </chart>

You seem to be using dataURL method, but you're providing value for dataXML parameter in renderChart function.

Thanks,
Pallav Nadhani
FusionCharts Team