Just to note that today I released a new version (v2.8.3) of this plugin (cf. Moodle2Word) so that it now handles questions containing badly formatted HTML.
Originally, Moodle2Word failed entirely to export questions where any component of any question in the selected category contained any content which was not well-formed XHTML. If chunks of text from Word are copied into the various question component fields in the editing form, they might not always be cleaned up properly by the rich text editor (TinyMCE?) before being saved. In addition, I have seen it mentioned that after a lot of editing, question components within the rich text editor can progressively become less well-formatted. The latest version resolves this issue, I hope.
Technical note: the plugin uses the PHP HTMLTidy extension to clean up text, if it's installed. If not, it uses the PHP strip_tags function instead, and makes a less reliable but still decent effort to ensure the export succeeds.