Which version of vCenter Server 6.0 are you running? 6.0 GA or U1/a/b? Are you running an embedded or external PSC?

Since SSO runs as part of the PSC it is expected to see "SSO is not initialized" when logging into the vCenter VAMI. When you log into the PSC VAMI (https://<psc fqdn>/psc) do you see everything as healthy? Is time synchronized between the PSC and Active Directory?