http://blogs.technet.com/b/chitpro-en/archive/2009/04/16/sql-server-2008-sp1-which-cus-are-included.aspxSQL Server 2008 SP1 states that Cumulative Updates 1 to 3 are included in it. For those customers who have CU4 already installed, you need to know how it affects you. Have a look on the CSS blog: http://blogs.msdn.com/psssql/archive/2009/04/09/sql-serveren-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)