Once the file is in Dropbox, Catalyst doesn't have anything to do with it, at least download-wise. So the link to the FAQ shouldn't be altered in any way based on something like that.
You also don't need to have an account with dropbox or have it installed to be able to download the file from them.
Are you following the link from the forum page or trying to right-click that link to download it?
The link on the forum isn't the file itself, it's the page where dropbox has it stored, so that could be your problem. If you haven't already, I would try following the link first, and then dealing with dropbox through the site. Again, you don't have to have it installed on your computer to download from the website.