Unable to sign into Messages on Mavericks
Context: I have two login keychains, one from an old MBP and the new one from this machine.

After deleting anything that had to do with Messages/Apple ID (including encryption keys, certificates, etc.) and killing the imagent and identityservicesd processes, Messages finally let me log in:


Apple ID n**@*****.com key (multiple of both public and private keys)
A bunch of old @me.com stuff (anything)
iMessage Encryption / Decryption Keys