In the 303 tree, specifically in the Fermi site part:
ftp://ftp.scientificlinux.org/linux/scientific/303/i386/sites/Fermi/SRPMS/
there's a file, which a bulk ftp fails to retrieve.
Looking at the thing by hand via ftp, I see this:
-rw------- 1 0 0 9117835 Oct 01 2004 acroread-5.08-2.src.rpm
suggesting that the ftp daemon cannot read it.
Hope this is useful.