We have received a few issue reports regarding Exchange 2007 SP2 installation breaking ORF to the point that only reinstallation helps – actually, you can fix the problem without reinstalling. If you are wondering what is happening, it is the good old CDOSYS vs. Exchange 2007 issue, where the Exchange 2007 installer corrupts the registration of 32-bit CDOSYS, resulting in ORF errors logged like “On Arrival error: Unexpected exception EEngineError “Error EOleSysError updating the MIME information: Library not registered””. The installer of ORF fixes the corrupted registration, but if you perform an in-place upgrade, the ORF installer will not run and thus you need to fix the problem manually. If you get the above error, check this FAQ article.