“Can not perform this action after onSaveInstanceState” - why am I getting this exception from my activity's onResume method?

Question

My activity invokes the camera with the ACTION_IMAGE_CAPTURE intent. If the camera activity returns succesfully, I set a flag in the onActivityResult callback, and based on

Answer 1

I think I know the answer - I'm using the FragmentActivity from v4 compatibility library, and so I need to perform my fragment transactions in onResumeFragments instead of in onResume. Can someone confirm?