In Django 1.4, ModelAdmin checks for inlines in a different way. This means that the way widgetry added inlines in tabs no longer works.
This patch adds a line that will populate the inlines in Django 1.4, while keeping the lines required for it to work with Django 1.3.
Django 1.4 compatibility with inlines in tabs
Thanks for fixing this. Saved me some hair-pulling.
We need all the hair we can keep.