Restore process fails with error 'is not a file' while copying

0.11.3ppa1~lucid1

upgraded from 0.10.x and upgraded the backups from 1.4 to 1.5 using the CLI utility.

while trying to revert my ~/.thunderbird directory, i get this error:

ERROR: Given copy source '/tmp/home/scar/.thunderbird/qnljpv54.default/lock' is not a file
Traceback (most recent call last):
  File "/usr/share/sbackup/sbackup/util/tasks.py", line 107, in __run_task
    result = self.__task(*args, **kwargs)
  File "/usr/share/sbackup/sbackup/core/RestoreManager.py", line 187, in revertAs
    failOnNotFound = False)
  File "/usr/share/sbackup/sbackup/core/RestoreManager.py", line 118, in restoreAs
    self._fop.force_move(_file_in_tmpdir, _file_in_target)
  File "/usr/share/sbackup/sbackup/fs_backend/_gio_utils.py", line 591, in force_move
    cls._copytree(src, dst)
  File "/usr/share/sbackup/sbackup/fs_backend/_gio_utils.py", line 618, in _copytree
    cls._copytree(srcname, dstname)
  File "/usr/share/sbackup/sbackup/fs_backend/_gio_utils.py", line 620, in _copytree
    cls.copyfile(srcname, dstname)
  File "/usr/share/sbackup/sbackup/fs_backend/_gio_utils.py", line 472, in copyfile
    _src, _dest = cls._prepare_copy(_src, _dest)
  File "/usr/share/sbackup/sbackup/fs_backend/_gio_utils.py", line 493, in _prepare_copy
    raise IOError("Given copy source '%s' is not a file" % src_gfile.get_parse_name())