Address List and EAP filter upgrades with Exchange Server 2007
Evan Dodds from the Exchange Product Group wrote a great blog a while back with regards to LDAP / OPATH and filters. If you have had any problems upgrading your address lists or running the /ForceUpgrade command and they don't work, please check here to see why: https://msexchangeteam.com/archive/2007/01/11/432158.aspx
This is a must read!!
Dave