Seems that it was a Python bug that has now been handled upstream: <http://bugs.python.org/issue14308> (thanks for the info, Peter Petrakis at <https://bugs.launchpad.net/duplicity/+bug/946993>).
In Sid, I no longer experience this problem. I guess it stopped when python2.7 2.7.3-1 was uploaded to Sid 2012-06-15. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org