Birt Chart Rendering Problems

I am not sure if this is the right place, but if it is not, I would appreciate if someone tells me which one is the right place for my question.

I created a report with 8 charts. The seventh chart is the only one that doesn't render properly. In the preview window while I am configuring the chart it looks good, but as soon as I preview the whole report the chart’s series doesn't take the dataset values but some arbitrary values I don't know from where they come. The odd thing is that it happens in the seventh chart and not in the eighth or nay other chart in the report.

Thanks in advance for any help you can provide me

GA