eTrust InoculateIT 6.0 with the "Incremental Scan" option enabled may certify that a file is free of viruses before the file has been completely downloaded, which allows remote attackers to bypass virus detection.
AV Option for MS Exchange Server option for InoculateIT 4.53, and possibly other versions, only scans the Inbox folder tree of a Microsoft Exchange server, which could allow viruses to escape detection if a user's rules cause the message to be moved to a different mailbox.