Resolved: Kerberos Authentication Service Problem
Last Thursday, August 2, 2012 from 6:19 a.m. through 9:43 a.m. one of the Kerberos KDC authentication servers was not receiving password changes and other account changes. By 9:48 a.m. that morning the problem KDC had caught up on updates. The other Kerberos KDC authentication servers were receiving updates and operating correctly.
This delay only affected users who used a service which authenticated against the problem KDC if they also had changed their Access Account password during that time, or if their Access Account had been created during that time.