webdav fails updating hidden directories

[JP]

Duplicity version: duplicity 0.7.02
Python version: Python 2.7.9
OS Distro and version: Ubuntu 15.04
Type of target filesystem: webdav

duplicity -v9 "/home/foo/.session/" "webdavs://user:<email address hidden>/foo/bar/.session"
WebDAV response status 409 with reason 'Conflict'.
Backtrace of previous error: Traceback (innermost last):
  File "/usr/local/lib/python2.7/dist-packages/duplicity/backend.py", line 365, in inner_retry
    return fn(self, *args)
  File "/usr/local/lib/python2.7/dist-packages/duplicity/backend.py", line 515, in put
    self.__do_put(source_path, remote_filename)
  File "/usr/local/lib/python2.7/dist-packages/duplicity/backend.py", line 501, in __do_put
    self.backend._put(source_path, remote_filename)
  File "/usr/local/lib/python2.7/dist-packages/duplicity/backends/webdavbackend.py", line 409, in _put
    raise e
 BackendException: Bad status code 409 reason Conflict.

Attempt 1 failed. BackendException: Bad status code 409 reason Conflict.