I had the latest version of OSX installed on my computer yesterday and I've lost my previous keychains. Now all the provisioning profiles result in the error that say "Xcode could not find a valid private-key/certificate pair for this profile in your keychain." The easiest solution is for me to delete the provisioning profiles, however I have an appstore submission that is using one of those distribution provisioning profiles. Two questions:
The following Technical Note from Apple will help you out I'm sure: Technical Note TN2250
Especially the section "Deleting/Revoking Your Certificates and Starting Fresh" might be helpful to you.