CHART_TYPE_BAR_H labels coming along x axis rather than y axis

I have the following to create a horizontal bar chart

<?php
$chart = array(
      '#chart_id' => 'test_chart',
      '#title' => chart_title(t('Poll Results'), '0000ee', 15),
      '#type' => CHART_TYPE_BAR_H,
      '#size' => chart_size(300, 400),
      '#grid_lines' => chart_grid_lines(20, 15),
      '#bar_size' => chart_bar_size(30, 15),
    );

$sql = "SELECT count(data) as count, data as label FROM table group by data";

$results = db_query($sql);
while ($result = db_fetch_array($results)){
       $chart['#data'][]        = $result['count'];
       $chart['#labels'][]      = $result['label'];
     }  

$chart['#data_colors'][] = chart_unique_color('test_a');

echo chart_render($chart);
?>

which works fine - except that the labels come along the bottom ie x axis, rather than along the y axis. Image attached.
Any ideas how I get the labels moved? thanks