MS may have invented it, but … is part of HTML 4: http://www.w3.org/TR/REC-html40/sgml/entities.html
Perhaps your Lib/htmlentitydefs.py is missing or out-of-date, as that's what BeautifulSoup uses to convert entities.
If you look at the Python 2.5 source tree you will clearly see it defined on line 126.
Gabe
2010-07-05 17:33:19