asterisk users - Nov 2006 - [FC5] How to update kernel/kernel-develop for Athlon?

Hello

I'm following instructions on how to install Asterisk on Fedora 5, but
I'm
having a problem:
- the host is an older "i686 athlon i386 GNU/Linux"
- /etc/rpm/platform says athlon-redhat-linux
- running "yum update kernel" downloaded "kernel i686
2.6.18-1.2200.fc5"
- running "yum update kernel-devel" wants to download
"kernel-devel i586
2.6.18-1.2200.fc5"

I know that I shouldn't mix versions (i686 and i586), but I don't know
how
else to update the system to make it ready for Asterisk.

=> Should I use a specific repository for Yum to use, or should I download 
a couple of RPMs to update those two items before proceeding with Asterisk?

Thank you.