FTP through HTTP download problem

[danjct]

Our company has 2 ftp sites. Internally, by opening a web browser (no proxy settings) you can browse the ftp site and click on a file. When you click on a file it gives you the option of downloading it (like it should). Externally, you can browse the ftp sites, however, when you click on the file to download it, it times out. You can right-click on the file and copy it, then paste it into explorer. You can also use command-line or WSFTP or CuteFTP to download the file. Why won't it let you download the file by clicking on it through a web browser externally, when you can do it internally? My reason is that the router does not have a certain port open to allow this function. Does anyone know how the router needs to be configured to allow this function to work. We have customers trying to download files and are timing out. The network guru's don't have a clue.

[Unibrow]

This is probably a stupid answer, but is it possible the files are not uploaded to the site? I am sry if this answer is stupid.