Yesterday we had an issue where the exchange information store would not start after a reboot. Our environment is Microsoft Exchange 2007 with all the update rollups installed, running on Windows 2008 R2 VM. The issue started out as all attachments being stripped from users emails.  We tried to restart all exchange and other services to try and resolve the problem and the information store suddenly would not start.  After a few hours of troubleshooting and finding no great information on google, i tried disabling the McAfee Security for Exchange Service, then rebooted the server, and the information store started right up.  The specific error I got was:

The Microsoft Exchange Information Store service terminated with service-specific error %%-2147467259.

A repair of the Mcafee Security for Exchange resolved the issue with the Mcafee product.  I hope this helps someone out.