Update Rollup 9 for Exchange Server 2007 Service Pack 1
MS Exchange Team released RU 9 for Exchange SErver 2007 SP1 but keep in mind that Exchange Server 2007 SP2 is just around the corner and it will bring all updates of the current RU 9 as well.
Update Rollup 9 for Exchange Server 2007 Service Pack 1 (SP1) resolves issues that were found in Exchange Server 2007 SP1 since the software was released. This update rollup is highly recommended for all Exchange Server 2007 SP1 customers.
RU 9 KB: http://support.microsoft.com/kb/970162
Download RU 9: http://www.microsoft.com/downloads/details.aspx?FamilyID=55320be2-c65c-48bb-bab8-6335aa7d008c&displaylang=en