I think this is the following issue: http://code.google.com/p/msysgit/issues/detail?id=298
Possible solution is to setup svnserve and use the svn:// protocol instead of file:///
See here for setting up svnserve on Windows:
http://tortoisesvn.net/docs/release/TortoiseSVN_en/tsvn-serversetup-svnserve.html
UPDATE
svnserve is available as a part of TortoiseSVN if you use Windows OS (I checked with TortoiseSVN version 1.8.6)
Then you just start:
svnserve -d -R --root c:\path\to\svn\repo
and clone the repository with following command:
git svn clone svn://localhost/path/inside/svn/repo