Ive looked though the code for the attachemtn stuff ...and dont really get it. Anyway if you print the query thats being run to get the $attachmentinfo data its
PHP Code:
SELECT a.userid, a.attachmentid, a.state, a.contentid, a.filename, fd.userid AS uploader, fd.extension, fd.filedataid, fd.dateline, fd.filesize, at.extension, at.mimetype, thread.forumid, thread.threadid, thread.postuserid, post.visible AS post_visible, thread.visible AS thread_visible
FROM vb_attachment...
or atleast that seems to be the query so why isnt everything after mimetype being shown?