(Sorry, I haven't used bitbucket for years and this is my first bitbucket pull request)
In upgrading my project to Django 1.6 I was unable to migrate because a change in Django's 'loaddata' method broke South's patching of it.
This fix seems to work. But could probably use some careful checking (monkeypatching is always fraught after all)
This was me: http://south.aeracode.org/ticket/1318