Charts: Gridlines display behind Columns after drill-down

Dec 6, 2012 at 2:31 PM

I have a WPF Chart control with gridlines on the Linear (Y) axis and have set IsSelectable to true so that I can click on a column and drill into the data.  On the selection changed command, I remove the existing column series and add the new series based on the selected column thus achieving a drill down report.

The only thing not working correctly is the gridlines now appear in front of the column data points.

Any ideas?