Why does Xcode auto-install a (duplicate and expired) certificate in the keychain? [duplicate]

Answer 1

I had the same experience with XCode 3 (not 4) and removing the old certificate in Keychain only wouldn't work.

I also add to remove all of my old provisioning profiles using the old certificate with Organizer then quit XCode, remove the old certificate from Keychain and restart XCode.

Now it seems to work fine!