Again, not recommended. You're talking about an FC1 server in this , not a true fc5 server.
Switching from distro to distro when you don't know what you're doing, or understand how to bail out IF it goes wrong, is VERY VERY BAD. In this case, there are no real benefits from going to CentOS4 from FC5, as the distributions are pretty much the same.
Since Fedora is the testing ground for RHEL and RHEL is the core for CentOS, you're essentially going from one OS to the next. No drastic changes will be made at all. You're simply jumping laterally, not doing any major upgrading.
Fedora will always be 1 version ahead, because that's how it's designed, at least as I understand it that is the case. Of course, I could be wrong, but IIRC that is correct. Right now we have fc6 in beta stage, and fc5 in somewhat stable, which was RHEL4 which was CentOS4.
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