Moving items in TreeView

This "works":

procedure TFormTestTreeView.TreeViewDragOver(Sender, Source: TObject; X,
   Y: Integer; State: TDragState; var Accept: Boolean);
begin
   if Sender is TTreeView then Accept := True;
end;

procedure TFormTestTreeView.TreeViewDragDrop(
   Sender, Source: TObject; X, Y: Integer
);
var TargetNode, SourceNode, NewNode : TTreeNode;
begin
   TargetNode := TTreeView(Sender).GetNodeAt(X,Y);
   SourceNode := TTreeView(Sender).Selected;
   if TargetNode = nil then
     TTreeView(Sender).EndDrag(False)
   else
     SourceNode.MoveTo(TargetNode, naAddChild);
end;

It moves the textitem but not the ImageIndex and StateIndex. The image 
doesn't move with it. Why not ? And how about the 
TTreeNode.Data-pointer? Although I only need the StateIndex.

Fons.