>> Is it a bug, per se?
If the editor adds a tag attribute and then rips it out then I can't see that it is anything other than a bug.
>> Out of curiosity, what happens if you go to Options -> Writing and uncheck the option: "WordPress should correct invalidly nested XHTML automatically"?
Its not checked.
The bug only happens, it appears, when I add a post with the WYSIWYG editor. I've added a draft post using w.bloggar and then editied it repeatedly and while the editor does indeed modify the HTMl adn moves the tag it does not remove it.
I need to confirm this with another site author who is using ecto on the Mac.
It only removes it, AFAICT, when I use the WYSIWYG editor.