The first source of my problems is duplicate private keys in the key chain, from the synchronization of Mobile Me and several Mac owners. This is what I propose to solve this problem once and for all. (Indeed - since I made this provision, it was as simple as I could imagine.)
Access Keychain on all of your Mac computers. Delete all your public and private keys. Create a new certificate request and you must have exactly one public and private key. HAVE this pair by double-clicking in Keychain Access - mercilessly kill all the other keys! (you cannot rename it, as you do something in Finder, you need to open the window by double-clicking). I named my "secret key" by Adam Eberbach Singleton. Export this key pair and then import them to other computers. Keep it forever, but, of course, do not share your private key with others.
The worst thing that happened as a result of deleting all of these keys was to log into a couple of websites again. I would like to know if there could be other consequences?
Once you have one true key pair, go to developer.apple.com and remove all of your certificates and provisioning profiles. Create new certificates using one of them.
Make sure your package identifiers are correct for your applications - you can even generate new application identifiers.
After that, you will create a training profile. If you have a valid certificate, application identifier and keys, you should not have any problems. A training profile is a bit that really matters, but it depends on everything else. The big test for me is when I drag it into the Xcode Organizer library - if the target then allows me to sign the assembly with a certificate mapped to the provisioning profile, I'm pretty sure.