Even with the release of Xcode 4 by Apple, each time I launch Xcode it magically resurrects an expired certificate id out of the kindness of it’s heart – creating a duplicate for me in Keychain Access. So I can’t build, etc. until that’s resolved. Each time.
If I launch Keychain Access and selected the expired certificate, hit the delete key on my keyboard & then use the return key (not clicking on the ok button), it removes the certificate but does delete it. Clicking on the button handles things properly.
Besides the whole resurrection thing, this dialog button seems like a bug to me in Keychain Access. Hello Friday bug reporter.