invalid attachment problem

[Macsee]

The source code is in the form of

<a href="http://myforums.com/attachment.php?attachmentid=137"  title="Name:  
Views: 
Size:  ">Attachment 137</a><br />

This is driving me nuts

I've spent all morning trying various things. I've logged on as one of the users who has several times in the past used attachments in his posts which are now leading to the invalid attachment message. I've created posts using his ID and added attachments to those posts.

I then had a look in the database. A couple of his attachments have a long entry in the posthash column of the attachments table. Example: c894c3d7090186aab36092639773d91f. Any idea what that is about? (Those show up with attachmentIDs in the tables, but with contentID of "0").

At least one of his old attachments seems to have completely disappeared from the database (the relevant number isn't in the attachmentID column). How could an attachment disappear from the database? I think this is the biggest problem.