scrollViewDidScroll never called

I had this "symptom" as well and lost about 2 hours of my life on it. I clearly had the delegate set correctly...but I did NOT know about setting the contentSize property on the scroll view. -.-

If you don't set that property, then the scroll view doesn't think there is anything to scroll to, and therefore will NOT trigger the expected scroll view methods.

The typical error is that "one does not simply set the delegate of a view". What you have probably forgotten is

theScrollView.delegate = self;