XenForo adds "http://"

If I make a link (to ftp://...) in a post, XenForo automatically prefixes it "http://". In fact, if I just type the text ( ftp://... ) XenForo automatically makes it a link and prefixes it with "http://".

Can I work around that or can XenForo be made to not behave that way?

Now I'm going to simply type a valid URL (and not make it a link). I suspect that when viewed in the forum, it will appear as a link and it won't work!

It comes through in the notification e-mails that way too.

Trying the "Link" button... ftp://lucky.syr.edu

Nope, the colon disappears even in the Preview.

Vince, where do you see the http://? If it's in your browser's address bar, maybe it's automatically adding it since the URL is invalid without the colon.
You can see the "http://" if you submit your post, then "Edit" it ... put the cursor in the text and press the link button