gitweb/test/Märchen has an identity crisis

In the git repository, after git checkout -f:
potomac:~/git%git status
# On branch master
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
...
#       gitweb/test/Märchen

potomac:~/git%rm gitweb/test/Ma\314\210rchen
potomac:~/git%git status
# On branch master
# Changed but not updated:
#   (use "git add/rm <file>..." to update what will be committed)
#
#       deleted:    gitweb/test/Märchen

Aaaarghh!! There seems something inconsistent in the encoding
of the ä letter that confuses git on my Mac OS X system.
My environment has LANG=en_US.UTF-8 set, in case that matters.

Filename completion results in Ma\314\210rchen, but the index
encodes it as M\303\244rchen:
0107272   g   i   t   w   e   b   /   t   e   s   t   /   M   ?   ?   r
         147 151 164 167 145 142 057 164 145 163 164 057 115 303 244 162

The filesystem seems to be fine with either:
potomac:~/git%ls -l gitweb/test/Ma\314\210rchen gitweb/test/M\303 
\244rchen
-rw-r--r-- 1 bosch staff 17 2007-04-09 14:51 gitweb/test/Märchen
-rw-r--r-- 1 bosch staff 17 2007-04-09 14:51 gitweb/test/Märchen

Anybody has insights in what causes this? Thanks in advance!

   -Geert