Pie Chart shows wrong coordinates on Click

Hello there,

i am currently coding a Plattform to do some Buissiness Intelligence with vaadin. I currently implement drilldown.
So i can configure my System so that when someone clicks on specific category of a chart (Pie/Column) he can choose from differeen t drilldown Options. I want the Options Window to pop up where the user clicked - so i use a PointClickListener - i get a PointClickEvent.

onPointClick(PointClickEvent event)
Window optionWindow = new Window();


When working with Column charts everything is fine, but when using pie charts i get the coordinates of the left upper corner of the Chart itself instead of the coordinates of the mouse-cursor.

Can anyone tell me what is wrong her? Is this a known issue?

Thank you!