Update Rollup 2 for Exchange Server 2007 Service Pack 1 has been released
Update Rollup 2 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.
Get it here: http://www.microsoft.com/downloads/details.aspx?FamilyId=99DA32E0-D9E3-4156-AABF-8369BF96E3E7&displaylang=en
List of changes that are included in this rollup: http://support.microsoft.com/?kbid=948016