Do you aware of Exchange Server 2007 Servicing? What is it...
Microsoft Exchange Server 2007 is serviced differently from earlier versions of Exchange. The servicing method that is used for Exchange 2007 offers several advantages over previous servicing methods. However, this servicing method differs slightly for hotfix contents, Windows Installer technology, and updates.
Please go through the following TechNet article describes these differences and provides guidance about how to best deploy fixes for Exchange 2007. It talks about various topics including Engineering Improvements, Installer Technology, Deployment Order, 32-bit vs 64-bit, Outlook Web Access (OWA) Customization, Release Schedule and distribution methods, Interim Updates and Update rollup ineraction etc.; also it provide important information about how Microsoft services and updates Microsoft Exchange Server 2007. These topics outline the servicing strategy for Exchange 2007, list the updates that are available for Exchange 2007, and provide basic information about how to apply the appropriate updates.
Really a handy to check-on!!