after syncing portage tree and issuing emerge -uavND world where : sys-auth/pam_krb5-4.3 sys-auth/consolekit-0.4.2-r4 sys-auth/pambase-20101024 packages got updated, the login interaction, suid, anything where change of credentials is taking place get bogged down. In other words, it is pig slow.
Going back to last previous stable consolekit & pambase fixes the problem.
This has nothing to do with security.
I see, didn't know. The packages have sth to do with security though :) Sorry, if I killed someone.
If you're not using Kerberos for logging in, don't enable USE=kerberos on pambase, simple as that…