HFS+ Unicode weirdness

On a brand new clone of git.git the file "gitweb/test/Märchen" is provoking some weird behaviour running on Mac OS X and the toy HFS+ filesystem. Note how the unmodified checkout of the file is shown as "untracked" by "git st", but on deleting the file it's shown as "deleted". If I build a copy of Git based on the clean working tree then the resulting build has a version number of "1.5.x-dirty".

Any suggestions on where to start investigating the cause of this? About the only lead I have is that if I create a file with that name by typing it's name it's encoded as "Ma\314\210rchen", but the file in the git.git repo is encoded as "M\303\244rchen".

Cheers, Wincent

$ git clone git://git.kernel.org/pub/scm/git/git.git
Initialized empty Git repository in /tmp/git/.git/
remote: Generating pack...
remote: Counting objects: 12259
Done counting 58277 objects.
remote: Deltifying 58277 objects...
remote:  100% (58277/58277) done
Indexing 58277 objects...
remote: Total 58277 (delta 40699), reused 58034 (delta 40521)
  100% (58277/58277) done
Resolving 40699 deltas...
  100% (40699/40699) done
$ cd git
/tmp/git
$ git st
# On branch master
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#       gitweb/test/Märchen
nothing added to commit but untracked files present (use "git add" to  
track)
$ ls -laF gitweb/test
total 24
drwxr-xr-x   5 wincent  wheel  170 Sep  4 14:18 ./
drwxr-xr-x   9 wincent  wheel  306 Sep  4 14:18 ../
-rw-r--r--   1 wincent  wheel   17 Sep  4 14:18 Ma??rchen
-rw-r--r--   1 wincent  wheel   31 Sep  4 14:18 file with spaces
-rw-r--r--   1 wincent  wheel   37 Sep  4 14:18 file+plus+sign
$ rm gitweb/test/Märchen
$ git st
# On branch master
# Changed but not updated:
#   (use "git add/rm <file>..." to update what will be committed)
#
#       deleted:    gitweb/test/Märchen
#
no changes added to commit (use "git add" and/or "git commit -a")