This might simply be a problem with the kernel you are booting. You might wanna make sure that the kernel you are booting does refer to the proper /lib/modules folder that it's trying to access. This was the only time I ran into that same problem. I was running a different kernel than I was trying to compile against. To fix the problem, I now mv /lib/modules/<kernelversion> /lib/modules/<kernelversion>.old and then "make modules" "make modules_install" with my new kernel. Then after everything is running great, I rm everything from the old kernel, including the kernel and the /lib/modules directory it's referring to.
This might also be that you didn't copy over the System.map file from the base directory of the kernel you updated.
I reread your problem, so replace "you" with "redhat update"
I hope that helps, at least to identify the problem a bit more. From there troubleshooting might be a bit easier (just a kernel rebuild).
Also... Why the old kernel?
Ok, now that I am at the end, I re-read your question again, and realize I am really not helping much. But for what it's worth, I will still post this in case it does help somewhat.