Unable to remove formatting on node edit

Hi,

Not sure whether this counts as bug or feature request.

When editing a node, you may apply and remove a style [tags are inserted/removed] using the buttons.
However, this only applies to changes made within that edit session.

If the node is saved, and then re-edited, the formatting from the previous edit cannot be removed.
Eg if a section of text is italic, the italics cannot be removed by selecting the italisised text, and then clicking the italic button.

Great to see this module keep improving - I'm almost ready to start using it in production

Regards
Alan