When I drag the mail to the intended folder, the folder will be highlighted for just an instant (flash).  When I release the mouse button, the mail floats back to the inbox and does not move (most of the time) even thought the mouse pinter has not moved away from the folder title / folder icon.  

It's as though there is a focus issue in which the mouse pointer only gains focus on the folder for just an instant, then it redirect somewhere else.

This is a very basic function in managing ones mailbox.  What is the solution??