So even if only one section in MS Word is protected against changes, then Word disables the ability to track-changes or add comments globally for *ALL* sections. Unfortunately the Table of Contents in OOo is by default a read-only element, because editing it is a bad thing to to as your changes will be blown away the next time the toc is automatically updated. So…
OOo->export to .doc->read-only OOo toc becomes a word toc in a readonly section->word refuses to insert comments anywhere in the doc, even though you can manually edit the rest of the sections in word.
Sigh, *drums fingers*. Basically it’s bustage in word isn’t it, but still a problem. No bug in OOo. Changing the OOo default to make TOCs editable would “fix” it, but suboptimal. Not exporting readonly sections as such is wrong as well.
Clearly, hacking the special case of exporting a TOC that is set to read-only to output an editable section is broken too, but might be the best solution.