It has been a while since I last visited the forum. I noticed this post in the tutorial. I checked the User Control Panel and the list of attachments were indeed still there but when I clicked one of them, the forum displayed the following:
The selected attachment does not exist anymore.
The file ./../files/358_686a2269744ce97fc41270cd85902572 does not exist.
Was there a forum purge at some point in the past and the attachments got deleted? I no longer have the original media files for that tutorial, otherwise I would have just re-uploaded them. Thanks.