Looks like MS have released an Update Rollup 1 for Exchange 2007.
The details can be found here:
The update covers the following issues:
Update Rollup 1 for Exchange 2007 includes the following fixes:
932487 (http://support.microsoft.com/kb/932487/) The Microsoft Exchange Information Store service stops unexpectedly when the Exchange Server 2007-based server replicates the Public folder
929756 (http://support.microsoft.com/kb/929756/) The DoSnapshotSet method may stop responding in the Exchange store, and a backup application stops responding on an Exchange 2007 server
Another thing for people to look at regards Exchange 2007!