SharePoint Dragons

What happens if a person leaves your organization and, as a consequence of that, somebody throws away the Active Directory user account, only to found out later that it still lingers on in SharePoint? You won’t be able to recreate the user because it’ll have a different SID, so what to do?

Use ol’ stsadm to the rescue: http://technet.microsoft.com/library/2a090c60-696f-4b68-8b6c-a19b763c60d3.aspx It allows you to migrate a user account to a new login name, optionally ignoring the SID meta data history.