At least until up2date learns to skip mirrors with missing files (bug 116479), the mirror list at http://fedora.redhat.com/download/up2date-mirrors/fedora-core-rawhide should only include mirrors that offer all platforms, not just i386 (or there should be separate multi-platform lists). Currently http://fedora.redhat.com/download/up2date-mirrors/fedora-core-rawhide lists http://mirror.hiwaay.net/redhat/fedora/linux/core/development/$ARCH/ which only has the i386 Raw Hide...
The mirror you point out has all the architectures now. Is there any mirrors that only mirror i386 arch at this point?
Yes - for example, http://distro.ibiblio.org/pub/linux/distributions/fedora/linux/core/development/$ARCH/ only works for ARCH=i386.
Note that FC2 is no longer supported even by Fedora Legacy. Also, up2date has been replaced by pirut and pup since FC5. FC3 and FC4 are supported by Fedora Legacy for security issues only. If this still occurs on FC3 or FC4 and is a security issue, please reopen and assign to that version and Fedora Legacy. If it occurs on RHEL 3 or 4, please reassign or refile against that product. The codebase for pirut and pup is quite different, so existing bugs do not apply, but please continue testing them on the still supported versions of Fedora Core and file bugs as necessary.