When you follow the steps to download a SQL Server 2005 (SP2/SP3) or SQL Server 2008 (RTM/SP1) cumulative update, you see a list of packages where you need to chose which ones you want to download and, normally, you have doubts about which one or ones you need to select. Should I download SNAC package also ??? The SQL PSS team create a blog post about this topic. Please, read it carefully:
Should I have a SNAC with my cumulative update?