When testing the charts views module I get all data points equal to zero. This is due to line 160 in chart_views/views/chart_views_plugin_style_chart.inc. Upon reverting the change in c16402b the charts started behaving correctly. I am using Drupal 7.14.

The line in question:
$field_value = isset($field_value[0]['value']) ? $field_value[0]['value'] : 0 ; // this would be nicer in 1 line.