Consider the following scenario:
- You configure the User Profile Synchronization service in Microsoft SharePoint Server 2010.
- You have an msOnline-UserPrincipleName attribute in the Active Directory domain schema.
- You synchronize the user profile.
- You create a My Site page for the user profile in SharePoint Server 2010.
This issue occurs because the msOnline-UserPrincipalName attribute is a reserved attribute in the Active Directory domain schema.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.