We re-released SQL Server 2005 SP2 on March 5th after discovering an issue with maintenance plans and associated cleanup tasks. If you want the gory details behind what happened and how you would possibly be affected if you downloaded and applied SP2 before March 5th, read the following KB article: http://support.microsoft.com/kb/933508 . The bottom line is if you installed SP2 before March 5th, we have a General Distribution Release (GDR) available at http://www.microsoft.com/downloads/details.aspx?FamilyId=e2c358a1-ecc4-4c49-8f65-daa6b7800eec&displaylang=en.
This update is also referred to as a critical update. This GDR fix (I'm going to call this GDR1) was also available via Microsoft Update so you might have already been notified of this update. If you applied SP2 on March 5th or later, you have a version of SP2 that already has this fix (that was what we included in the re-release). The issue here was specific to clean-up tasks.
Source:→ PSS SQL BlogMicrosoft, SQL, Server, SQL Server 2005, Service Pack, SP, Release, Fix