IncrementalDumpError: Can't add a path that already exists

While trying to convert an SVN repository over to bzr, I get the following exception:

Revision 1258 read
Traceback (most recent call last):
  File "svn2bzr/svn2bzr.py", line 194, in <module>
    main()
  File "svn2bzr/svn2bzr.py", line 187, in main
    log=log)
  File "svn2bzr/svn2bzr.py", line 78, in svn2bzr
    dump = Dump(dump_file, log=log) # read through the whole dump file
  File "/home/luke/Desktop/svn2bzr/dump.py", line 111, in __init__
    self._read()
  File "/home/luke/Desktop/svn2bzr/dump.py", line 448, in _read
    building=True)
  File "/home/luke/Desktop/svn2bzr/dump.py", line 260, in _change_tree
    raise IncrementalDumpError("Can't add a path that already "
dump.IncrementalDumpError: Can't add a path that already exists

No matter what options I pass to svn2bzr, it always crashes on the same revision.