As a specific example, I have an uploads directory (using drall) on my family web site where people can share photographs, etc., and an InterWiki link to that directory.
To work around this, I can enter the entire URL (
http://www.popkinhartel.com:8000/uploads/cutekid.jpg) which displays properly. The problems are that (1) this is way more typing, and (2) I end up with the machine name and path embedded in every page, so if either of those changes I have to edit all over my Wiki. Simply editing the InterWiki file is, of course, much better.
I'd make the change myself, but I don't know Perl well, and the code is pretty contorted so I'd rather leave it to someone who's already wrapped their heads around it if I can.