Why try to go to FC5? Why don't you just upgrade directly to something up-to-date, and longer lived? Say, CentOS 5? Your chances of the upgrade going smoothly are probably just as good as trying to go through the older Fedora distros (which, in my experience, is seldom smooth anyway - all sorts of changes have taken place since then - such as changing the HD drivers from seeing IDE drives as HDA to SDA - and typically not converting the fstab file properly post change... )