I wanted to post a quick post about the rollup 6 that was released last week, as there seems to be some misunderstanding about what it applies to:
Rollup 6 is for machines running Exchange 2007 Release to Manufacturing (RTM) version.
Rollup 6 is therefore not for machines running Exchange 2007 Service Pack 1 (SP1).
To explain this further: Exchange 2007 SP1 includes all of the fixes that were included in first 5 rollups for Exchange 2007 RTM. As rollup 6 was being worked on during the time that Exchange 2007 SP1 was being finalized, the fixes that are in rollup 6 for RTM are not in Exchange 2007 SP1. However, there will be a post SP1 rollup released for Exchange 2007 SP1 machines which will give you the fixes that rollup 6 for RTM has. Stay tuned for that, you will read about it on this blog.