I have upgraded to python-lxml 2.3.5-1 from http://snapshot.debian.org/package/lxml/2.3.5-1/ , which is readily installable in wheezy, and as expected the conversion works. I will continue to test and use calibre with this version and report any problems here.
Pavel -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org