I am not quite sure about the way that you bind the ListBox. The issue is because the transfered items and not actually deleted from the DB. So it is showing the same data after refreshing.
supports automatic database updates.For that the listbox must be bound to a declarative
which has its UpdateCommand and/or DeleteCommand
If this is your scenario, then set the TransferMode
as Move .
When an item is moved then also the deletion takes place automatically.
Check out the following help article for more on this.
Automatic Database Updates
Another suggestion is to delete the item explicitly on moving the Item.