When a new TableCell instance is created by TableView for a given cell, the previous TableCell instance for that cell will continue to respond to edits (i.e. startEdit() gets called when you double-click on that cell) until it is finally eaten by the garbage collector. New TableCell instances seem to be created when a TableView's item list is added to or when it is swapped out.

This becomes a problem when custom TableCell subclasses are used. I have a custom TableCell class that shows a dialog window after startEdit is called... when multiple TableCell instances exist for a cell, I get multiple dialog windows appearing in succession. The more I edit the item list of the TableView, the more dialogs I get when I try to edit a cell!

Bottom line: when a TableCell is replaced, it should no longer respond to editing in the TableView.