Hi Tom,
SP2 treats 2005 maintenance plan units (IE delete maintenaince history after x days and delete history after x days) as hours rather than days. So if your maintenance history used to be deleted after 3 days it will now be deleted after 3 hours Nice huh.. More information on it here: http://blogs.msdn.com/sqlrem/archive/2007/02/24/Maintenance-Plan-Changes-in-SQL-Server-2005-SP2.aspx but the short version is after an SP2 upgrade you must edit your maintenance plans and change the unit values.
- James