Windows version of git unable to pull from OSX version of git

I have two repositories on my OSX partition that work perfect. When I dual boot into windows, I want to clone the project. I've installed cygwin/git and have the osx drive mounted on Z: . I can't seem to do a git submodule update in windows under cygwin without getting errors (the same commands work fine when I am booted into OSX). I've tried both the cygwin and msysgit, and they both exhibit the same problem.

$ git submodule update Initialized empty Git repository in /cygdrive/d/Visual Studio Projects/ project/base/.git/ Submodule path 'base': checked out '745659513bf3bbd1e57ac26a99101a200a42a97a' Initialized empty Git repository in /cygdrive/d/Visual Studio Projects/ project/common/.git/ fatal: git-upload-pack: cannot find object 016f0e3580a263d441a246e74e27d6c73960e 524: fatal: The remote end hung up unexpectedly Clone of '/cygdrive/z/Users/max/git_repositories/common/.git' into submodule path 'common' failed

max@m-ff21e0b3bd974 /cygdrive/z/Users/max/git_repositories/test7 $ git submodule update Initialized empty Git repository in /cygdrive/z/Users/max/ git_repositories/test7/base/.git/ error: index file ./objects/pack/ pack-65a6edbb59ff536215053396a58386692ac7e067.idx is too small error: index file ./objects/pack/ pack-65a6edbb59ff536215053396a58386692ac7e067.idx is too small fatal: git-upload-pack: cannot find object 25ee9b0c85086b830e4d4c9eda6bd7bd5dd85 ee2: fatal: The remote end hung up unexpectedly Clone of '/cygdrive/z/Users/max/git_repositories/project/.git' into submodule path 'base' failed

Any ideas? I've tried git gc to fix any problems but it returns fine. git fsck warns of dangling binary blobs but that's it. I've also tried to copy the git repositories over to the windows partition but the error is identical. Any help is appreciated. I don't want to go back to SVN :-(