Update Rollup 4 for Exchange Server 2007 (KB 940006) has been released (thanks for the info Scott!). The update is live at:
It will also be offered via Microsoft Update later today.
The KB should be live soon.
http://support.microsoft.com/?kbid=940006
List of escalated issues fixed in Update Rollup 4
KB
Title
930463
Missing Recipients on Edge cause 5.1.1 NDR, Edgesync does not Sync objects from Other domain trees in Same Forest
937656
Change to DST transition dates in New Zealand time zone starting 2007
936300
Mailbox Moves Blocked due to store deadlock
NA
Dismount Fails When Run As Local System
NA
Cancelling a backup from replica writer leaves store in backup in progress state, store restart is required in order to continue the backups successfully
932561
Implement Western Australia DST time zone
NA
Test-edgesync needs to compute proxyaddress hash only once to avoid false positive in multi-edge server scenario
937861
Exchange Gives Borked Address Type Array to Client, Causing NDR
938359
Store.exe crash while composing a standard reply for moderated email-enabled public folder
938698
LLRPerf: Long running open transactions are causing the checkpoint adv to be tricked into thinking it needs to version pages
936716
Date format in body of read receipt confirmation does not match OS regional settings
940052
Unable to reconnect a mailbox through EMC
933314
ADSizelimitExceededException when GetDefaultAcceptedDomain() is called
939560
EcGetSTF will only return maxPageSize number of OABs, not enough for hosting systems