Minor Description
When the AbstractColumn#populateItem adds a Panel which uses the MarkupComponent#queue method to add its children, the following error occurs: Detach called on component with id 'cell' while it had a non-empty queue.
If the queue methods are changed to add, everything works. This is the workaround.
In the attached file, the problem is ActionPanel (which is added by ActionColumn). Changing queue to add makes the example work.