Shoutbox

Well, since each ID is unique to a file you don't want them to "refresh" each time a change occured in your files list. Imagine for example that someone is used to get a specific file, he can just come in and request the file with the id right away, if that ID changes all the time, that may confuse your users.

Something that would be interesting though is to offer the user to refresh all the IDs (without doing it automatically).