Default values on Server editions:
Logon: Success, Failure
Logoff: Success
Account Lockout: Success
IPsec Main Mode: No Auditing
IPsec Quick Mode: No Auditing
IPsec Extended Mode: No Auditing
Special Logon: Success
Other Logon/Logoff Events: No Auditing
Network Policy Server: Success, Failure
You need to make sure that you also have Auditing enabled on the default domain controllers policy as well.
http://www.lepide.com/lepideauditor/active-directory.html
Will.