This actually depends on how the user (in ACS) was created.
If you manually enter a user with password type set to AD - the user will always be in the group you assigned at creation time (or re-assigned during an edit)
If the user was auto-created by the unknown user policy - then the group setting will be dynamic and assigned via the group mapping policy for the external authenticator.
It sounds like some of your AD users have been manually assigned groups within ACS. Provided your unknown user policy is working yhou could simply delete the users in ACS and let them get auto-recreated.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...