Encoding not working for charts with more than one data set

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Create a line chart with more than one data set.
2. Set the encoding.
3. Display the chart.

What is the expected output? What do you see instead?
The chart doesn't load any data set at all.

What version of the product are you using? On what operating system?
Latest. 0.6.3

Please provide any additional information below.
        $lineChart = new gLineChart(500,300);
        $lineChart->setEncodingType('s');
        $lineChart->addDataSet($series);
        $lineChart->addDataSet($series2);
        echo '<img src="';
        echo $lineChart->getUrl();
        echo '" /><br/>' . PHP_EOL;

Original issue reported on code.google.com by josepva...@gmail.com on 1 Dec 2010 at 1:47