### Please describe the problem.

When syncing with a remote, I get some files with "unknown backend".

Original:

    $ ls -lh Pictures/2014/06/21/2014-06-21\ 13.52.34.png
    lrwxrwxrwx 1 jean jean 214 Jun 21  2014 Pictures/2014/06/21/2014-06-21 13.52.34.png -> ../../../../.git/annex/objects/mx/Ff/SHA256E-s247069--d425c1049778880eb9b9fcab74a82ec86dd22882db9c026f8fc0e9cb6270d022.34.png/SHA256E-s247069--d425c1049778880eb9b9fcab74a82ec86dd22882db9c026f8fc0e9cb6270d022.34.png

This picture and symlink is fine.

Remote (broken symlink):

    $ ls -lh Pictures/2014/06/21/2014-06-21\ 13.52.34.png
    lrwxrwxrwx 1 jean jean 214 Apr  6 12:50 Pictures/2014/06/21/2014-06-21 13.52.34.png -> ./../../.git/annex/objects/mx/Ff/SHA256E-s247069--d425c134ac2f9b0eb9b9fcab74a82ec86dd22882db9c026f8fc0e9cb6270d022.34.pn0.png/SHE-s247069--d425c1049778880eb9b9fcab74a82ec86dd22882db9c09efe84ca9cb6270d022.34.png

In this case the paths differ: there is an extra `.pn0` component, and the final `SHA256E` has changed to `SHE`.

### What steps will reproduce the problem?

I don't know yet.

### What version of git-annex are you using? On what operating system?

    $ git annex version
    git-annex version: 5.20140412ubuntu1
    build flags: Assistant Webapp Webapp-secure Pairing Testsuite S3 WebDAV Inotify DBus DesktopNotify XMPP DNS Feeds Quvi TDFA CryptoHash
    key/value backends: SHA256E SHA1E SHA512E SHA224E SHA384E SKEIN256E SKEIN512E SHA256 SHA1 SHA512 SHA224 SHA384 SKEIN256 SKEIN512 WORM URL
    remote types: git gcrypt S3 bup directory rsync web webdav tahoe glacier hook external
    local repository version: 5
    supported repository version: 5
    upgrade supported from repository versions: 0 1 2 4

Ubuntu 14.04.1 LTS

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log

$ git annex info
repository mode: indirect
trusted repositories: 0
semitrusted repositories: 6
        00000000-0000-0000-0000-000000000001 -- web
        ...
untrusted repositories: 0
transfers in progress: none
available local disk space: 168.35 gigabytes (+1 megabyte reserved)
local annex keys: 16503
local annex size: 39.15 gigabytes
annexed files in working tree:
  skipping Pictures/2014/06/21/2014-06-21 13.52.34.png (unknown backend SHE)

  skipping Pictures/2014/06/21/2014-06-21 13.52.45.png (unknown backend SHE)

  skipping Pictures/2014/06/21/2014-06-21 13.58.03.png (unknown backend SHA256EE)
104552
size of annexed files in working tree: 124.64 gigabytes
bloom filter size: 16 mebibytes (3.3% full)
backend usage:
        SHA256E: 121054
        SHA256: 1

$ git annex get --from=laptop

  skipping Pictures/2014/06/21/2014-06-21 13.52.34.png (unknown backend SHE)

  skipping Pictures/2014/06/21/2014-06-21 13.52.45.png (unknown backend SHE)

  skipping Pictures/2014/06/21/2014-06-21 13.58.03.png (unknown backend SHA256EE)


# End of transcript or log.
"""]]

[[!tag moreinfo]]