Make a folder. Make a sub folder. Drag parent folder into child. They both disappear and throw this bug:

ava.lang.IllegalArgumentException: new child is an ancestor
at javax.swing.tree.DefaultMutableTreeNode.insert(DefaultMutableTreeNode.java:165)
at com.affymetrix.igb.bookmarks.BookmarkList.insert(BookmarkList.java:88)
at javax.swing.tree.DefaultTreeModel.insertNodeInto(DefaultTreeModel.java:218)
at com.affymetrix.genoviz.swing.DragDropTree.drop(DragDropTree.java:153)
at java.awt.dnd.DropTarget.drop(DropTarget.java:434)
at sun.awt.dnd.SunDropTargetContextPeer.processDropMessage(SunDropTargetContextPeer.java:519)
at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchDropEvent(SunDropTargetContextPeer.java:832)
at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchEvent(SunDropTargetContextPeer.java:756)
at sun.awt.dnd.SunDropTargetEvent.dispatch(SunDropTargetEvent.java:30)
at java.awt.Component.dispatchEventImpl(Component.java:4592)
at java.awt.Container.dispatchEventImpl(Container.java:2143)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4621)
at java.awt.LightweightDispatcher.processDropTargetEvent(Container.java:4356)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4207)
at java.awt.Container.dispatchEventImpl(Container.java:2129)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:679)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:638)
at java.awt.EventQueue$1.run(EventQueue.java:636)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:652)
at java.awt.EventQueue$2.run(EventQueue.java:650)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:649)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception in thread "AWT-EventQueue-0" java.awt.dnd.InvalidDnDOperationException: invalid rejectDrop()
at sun.awt.dnd.SunDropTargetContextPeer.rejectDrop(SunDropTargetContextPeer.java:627)
at java.awt.dnd.DropTargetContext.rejectDrop(DropTargetContext.java:191)
at java.awt.dnd.DropTargetDropEvent.rejectDrop(DropTargetDropEvent.java:225)
at com.affymetrix.genoviz.swing.DragDropTree.drop(DragDropTree.java:168)
at java.awt.dnd.DropTarget.drop(DropTarget.java:434)
at sun.awt.dnd.SunDropTargetContextPeer.processDropMessage(SunDropTargetContextPeer.java:519)
at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchDropEvent(SunDropTargetContextPeer.java:832)
at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchEvent(SunDropTargetContextPeer.java:756)
at sun.awt.dnd.SunDropTargetEvent.dispatch(SunDropTargetEvent.java:30)
at java.awt.Component.dispatchEventImpl(Component.java:4592)
at java.awt.Container.dispatchEventImpl(Container.java:2143)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4621)
at java.awt.LightweightDispatcher.processDropTargetEvent(Container.java:4356)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4207)
at java.awt.Container.dispatchEventImpl(Container.java:2129)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:679)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:638)
at java.awt.EventQueue$1.run(EventQueue.java:636)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:652)
at java.awt.EventQueue$2.run(EventQueue.java:650)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:649)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)