Well, it does say that it could be because youre not logged in, but i logged out again and looked to see if i could reproduce the results i got last time, and i got the same.
It just directed me to
http://biorust.com/index.php?page=suberror
Its just a generic error page, and i posted because I didnt really read the print at the bottom, just the huge exclamation point and the words "User-Borne Error"
The print at the bottom does say that if i clicked a link to get here that it means i have to be a registered member (and logged in), but I think it would be better for it to simply say "You Must be Logged In to do that!" or something of that sort for things that you have to be logged in to do.
I figure most people (like me) will not pay attention enough to notice the print at the bottom. And yes it does say "File downloads are member-only features. Click here to register." right above the file download links, but I never noticed that until you mentioned it in your post.