Regarding TreeTable is not refreshing

iam using treetable add-on vaadin-treetable-1.2.2.jar, This jar solves my issue removing last item from my treetable(previously it appears,now its not appearing)

i got another problem with this…wn i collapse or expand all items from tree table and then i do drag and drop of items,they are not moving,the tree table is not refreshing

(when i do again collapse or expand items,then the items which are moved earlier are appearing).

please, can any one help regarding this issue.