Hi, Georg
If you haven't reviewed the FAQ site yet, you really should, including
http://word.mvps.org/macwordnew/docu...ioncontent.htm

Also, I understand that saving the document to HTML and opening the new
HTML version can leave a lot of problems behind.
However, not all Word document features survive the trip through HTML.

I would also be tempted to create a new .dot file to associate yoru
document with, and leave that .dot file unlocked.
How's progress?
Regards
Jay