The Date resolution of the FAT filesystem is only 2 seconds for the "last modified time."
This leads to the strange behaviour, that after umount and remount of an usb drive (direct mode) git-annex thinks that suddenly approx. 50% of
the files are modified.  (after remount the "seconds" appears to be rounded to even values - the inode cache before unmount had 1 second resolution) So git-annex is not real "guilty" but it would be fine to create a "workaround" for this problem...

Possible the best solution for this is to set even values for the seconds in the filesystem and in annex internal tables direct after the `git annex get`. 
Other solution would be to treat differences up to 1s in modification time as unmodified or create an new parameter like rsync's "modify-window" for this. To do an `git annex sync` or `git annex add` is in my opinion not a good option, because one could add so Bad file content by accident...

Here's an konsole session to show this behaviour:

    $ mount /mnt/transfer/
    $ git clone source/ /mnt/transfer/transfer-repo

    Klone nach '/mnt/transfer/transfer-repo'...
    Fertig.

    $ cd /mnt/transfer/transfer-repo/
    $ git annex init "test"

    init test 
      Detected a filesystem without fifo support.

      Disabling ssh connection caching.

      Detected a crippled filesystem.

      Enabling direct mode.
    ok
    (Recording state in git...)

    $ git annex group here transfer

    group here (merging origin/git-annex into git-annex...)
    (Recording state in git...)
    ok
    (Recording state in git...)

    $ git annex wanted here standard

    wanted here ok
    (Recording state in git...)

    $ git annex get --auto

    get n01.mp3 (from origin...) 
    SHA256E-s1159018--5674452792970dc03e9ba47d3a8af5ad7c8da6b3ca19e8e64b9a4cf462d4a92d.mp3
         1159018 100%   82.62MB/s    0:00:00 (xfer#1, to-check=0/1)

    sent 1159308 bytes  received 31 bytes  2318678.00 bytes/sec
    total size is 1159018  speedup is 1.00
    ok

    get n02.mp3 (from origin...) 
    SHA256E-s1622113--03998dc10c4839d5ab9aeaceaa63f0363c9d728aaaca2a2707f025c7b9e920a3.mp3
     1622113 100%   34.45MB/s    0:00:00 (xfer#1, to-check=0/1)

    sent 1622459 bytes  received 31 bytes  3244980.00 bytes/sec
    total size is 1622113  speedup is 1.00
    ok

    ...
    ...

    –--> All 29 files (n01.mp3 to n29.mp3) successfully got

    (Recording state in git...)

    $ git annex status
    $ stat * >../stat-before-umount
    $ cd /
    $ umount /mnt/transfer 
    $ mount /mnt/transfer 
    $ cd /mnt/transfer/transfer-repo
    $ stat * >../stat-after-remount
    $ git annex status
    M n05.mp3
    M n10.mp3
    M n11.mp3
    M n13.mp3
    M n16.mp3
    M n17.mp3
    M n20.mp3
    M n22.mp3
    M n23.mp3
    M n24.mp3
    M n26.mp3
    M n27.mp3
    $ diff -u ../stat-before-umount ../stat-after-remount | grep -B8 "+Modifiziert" | grep -E "Datei:|Modifi"

       Datei: „n05.mp3“
    -Modifiziert: 2014-05-03 19:42:39.000000000 +0200
    +Modifiziert: 2014-05-03 19:42:38.000000000 +0200

       Datei: „n10.mp3“
    -Modifiziert: 2014-05-03 19:43:05.000000000 +0200
    +Modifiziert: 2014-05-03 19:43:04.000000000 +0200

       Datei: „n11.mp3“
    -Modifiziert: 2014-05-03 19:43:07.000000000 +0200
    +Modifiziert: 2014-05-03 19:43:06.000000000 +0200

      Datei: „n13.mp3“
    -Modifiziert: 2014-05-03 19:43:15.000000000 +0200
    +Modifiziert: 2014-05-03 19:43:14.000000000 +0200

       Datei: „n16.mp3“
    -Modifiziert: 2014-05-03 19:43:21.000000000 +0200
    +Modifiziert: 2014-05-03 19:43:20.000000000 +0200

       Datei: „n17.mp3“
    -Modifiziert: 2014-05-03 19:43:29.000000000 +0200
    +Modifiziert: 2014-05-03 19:43:28.000000000 +0200

       Datei: „n20.mp3“
    -Modifiziert: 2014-05-03 19:43:53.000000000 +0200
    +Modifiziert: 2014-05-03 19:43:52.000000000 +0200

       Datei: „n22.mp3“
    -Modifiziert: 2014-05-03 19:44:13.000000000 +0200
    +Modifiziert: 2014-05-03 19:44:12.000000000 +0200

       Datei: „n23.mp3“
    -Modifiziert: 2014-05-03 19:44:23.000000000 +0200
    +Modifiziert: 2014-05-03 19:44:22.000000000 +0200

       Datei: „n24.mp3“
    -Modifiziert: 2014-05-03 19:44:31.000000000 +0200
    +Modifiziert: 2014-05-03 19:44:30.000000000 +0200

       Datei: „n26.mp3“
    -Modifiziert: 2014-05-03 19:44:35.000000000 +0200
    +Modifiziert: 2014-05-03 19:44:34.000000000 +0200

       Datei: „n27.mp3“
    -Modifiziert: 2014-05-03 19:44:39.000000000 +0200
    +Modifiziert: 2014-05-03 19:44:38.000000000 +0200


> fixed [[done]] --[[Joey]]
