iPhone code signing and multiple clients
If you have to make a certificate request for a new client or "Team," avoid making your name the same as your current certificate. If you have more than one "iPhone Developer: Jonathan Saggau" on your keychain, Xcode doesn't know which to use for code signing. I used to swap certs in the keychain when switching between clients, but that proved confusing. Better to use "Jonathan Saggau (BigCO inc)" or some such when making your cert request. What you'll see when you do that is a pseudo-random string appendage to your name that allows certificates from different companies or "Teams" to coexist. While I'm not sure if this is just a change on Apple's part (maybe they always add the pseudo-random string now; I dunno) or if the (BigCO inc) string brings the magic. What I do know is that I no longer have to rejigger my keychain every time I want to build an app for client X after working on the app for client Y.