Here's a critical patch that has not received much press. If your running
Sybari's Antigen on an Exchange 2000 server, apply this patch immediately
(this patch is also included in the latest exchange rollup). The story here
is a bug in Microsoft's handling of event sinks causes corruption in the .stm
file. Sybari is aware of it and recommends installing it as well.
This one cost me a days work restoring a db. Fun stuff.
814891 - Error -613 Occurs When You Perform an Online Backup