Well, you said that those files of yours get hits which indicates that at least parts of the file names are included in other's search terms.
But as long as you have the brickwall in front of the small globe I doubt that the people will be able to download from you. The link I've posted for you is not only meant for download problems, it will also solve the upload issue.
Try to follow the links about configurating the router, which I believe is responsible for the brickwall (but just in case check the XP firewall as well).
