Ok, so I've asked a similar question already, but I'm now faced with a different issue on the same problem! I'm creating an iPad application and trying to replicate the Apple Mail App UI. Initially I could not update the DetailView because I was not updating the delegate when pushing a new navigation controller on the left view, this was resolved using:
newRootViewController.myDelegate = self.delegate;
I've included functionality from Apple's MultipleDetailViews code sample to include more than one detail view (using < SubstitutableDetailViewController >), but this stops the label from updating on the detail view.
I can resolve this issue by removing the connection between splitViewController and RootViewController using IB and then the label update works, although this [obviously] stops the multiple Detail view functionality from working.... any ideas?