What is the recommended way of getting the kernel-source package update that matches a kernel update retrieved with up2date? If I request source with up2date (either generally or specifically for the kernel rpm) I get complaints about error 404 file not found.
Which version of Fedora Core are you using? FC3 has no kernel-source package.
In general you can get the kernel src.rpm from the SRPMS directory of the Fedora updates directory for your distribution on your favourite Fedora mirror site.
Paul.