I also am experiencing this issue in my environment, and have been told by Cisco tac that this is not a serious issue.  It appears to happen within our environment once a week. Keen to hear how to resolve this.

I also experience this issue with in my environment, and was informed that the multiple requests for login is a known issue, however have not been able to get a definitive answer regarding performance.  Have you made any gains on this?thanksPeter