Across tree move on a TreeGrid (which is inside a ListGrid as expanded component)

Hey experts,

Need some advice from u guys..

Code pattern:-

1. I have a Window component.
2. The window component in turns contains a List Grid..
3. Each of the record in the ListGrid contains a TreeGrid [As an expansion component].

Problem:-

a. I have opened 2 Windows
b. Trying to perform drag and drop from one tree to another [From one window to another]
c. Although I have set following properties as true:-
i. canAcceptDroppedRecords
ii. canDropOnLeaves
iii. canDragRecordsOut
iv. showCustomIconDrop
d. The folderDrop function is never invoked. [Im also not seeing the drop icon to occur]

Can u guys guide me why the folderDrop function is not invoked when we are doing move between 2 trees [Within a single tree the move is working perfectly fine].

(Im on tight schedule now) Any suggestion would be of great help .

--Sam