FYI -- System>Component Management > Update status is where these update settings are buried. I let one of our boxes go and it seemed to be okay, though it wasn't routing much mail granted.
Here was an SNS alert from 2 days ago:
McAfee has confirmed that incremental DAT 6682 may trigger messagescan failures and a system crash in GroupShield Exchange (MSME), GroupShieldDomino, and McAfee Email Gateway 7 (MEG). McAfee recommends that customers do NOT upload DAT 6682.