java.awt.dnd.InvalidDnDOperationException: failed to create native peer: java.lang.NullPointerException: null native data for trigger event

Drag and drop does work though...

Compile and Run attached sample
manipulate both JCOlorChoosers so both can be viewed
click (no need to DnD) on the preview area, then click on the other preview area
keep cycling through this and you will see:

java.awt.dnd.InvalidDnDOperationException: failed to create native peer: java.lang.NullPointerException: null native data for trigger event
        at sun.awt.motif.MDragSourceContextPeer.startDrag(MDragSourceContextPeer.java:74)
        at sun.awt.dnd.SunDragSourceContextPeer.startDrag(SunDragSourceContextPeer.java:105)
        at java.awt.dnd.DragSource.startDrag(DragSource.java:308)