I have seen this on Windows, with msysgit 1.7.2.3. You have to fix the path to bin/curl-ca-bundle.crt. I had to specify the absolute path, using back-slashes:
git config --system http.sslcainfo "C:\Program Files (x86)\git\bin\curl-ca-bundle.crt"
This will result in changes to [git-install-dir]/etc/gitconfig file, which may be edited directly, too.
(Original solutions found at http://github.com/blog/642-smart-http-support)