[Solved] Drag and Drop column header problem in RadGridView

[peter]

Hello,

I am using RadControls for Silverlight 2010 Q3

I have a grid.  Instead of use the Group Panel in the grid, I create my own grouping panel use RadDragandrop manager  for the grid . My goal is to drag the head column of the grid to my own group panel . Everything works fine, but when I try to  reorder the column in the grid . It's doesn't work. If  I change the code to

if (e.Options.Source is GridViewHeaderCell)
{
    return;
}

the reorder columns works again. but my own group panel doesn't work.
Is there a workaround for this? 

Thanks,

Jeff