Are you using Outlook by any chance? If you are, mostly "src=CID" only appears in the View-Source via Outlook. It's a reference to the downloaded image saved in the temp files on your desktop. If you look at the raw mail file on the server before downloading the message, there is a regular "img src='http:// ". So SA would never detect 'CID' anyway - it only exists after downloading.
BTDT - I found this out when a procmail recipe I tried kept failing! Jo