Track HTTP redirects in NSURLSession

Question

I have a strange bug with my network-connected app. It retrieves a JSON feed from a server and present those in a news-like interface. I use the newly released NSURLSession, with a data task. Now just yesterday there has been a change of server, that involved a temporary redirection of main domain to subdomain of new provider, the time the DNS propagate correctly. Today the main domain correctly points to the new server.

The transition went smoothly on the web, but I am facing some problems with my app. I constantly have a "too many http redirects" error. When I delete the app and reinstall it (either the previously released version from the Store, or the current development version) the problem goes away. But when I don't delete the app, the problem remains, even if the app is killed and even overwritten (i.e. new version installed without prior deletion).

When I display the json in my web browser, it displays without a problem, including on the iPhone mobile Safari browser. And again, it also displays without a problem when the app has been reinstalled.

This is becoming really annoying to debug. I am now looking for a way to track those alleged redirections to see where the problem may arise from.

This problem looks similar to one experienced by many users' App Store app. I suspect a bug in the Cocoa SDK, but without any detail on what's actually happening I cant even file a radar.

Any hint would be appreciated.