The kernel-headers package that gets installed is for 2.4, not 2.2.16. This is before trying to load the 2.4 preview. The files RedHat/RPMS/kernel-headers-2.4.0-0.26.i386.rpm and preview/RPMS/kernel-headers-2.4.0-0.26.i386.rpm are the same file.
*** This bug has been marked as a duplicate of 15016 ***