How to create a custom rescue disk

[Richard Ray <rray mstc state ms us>]

Can someone point me to info on how to replace the isolinux/vmliunz on 
FC3-i386-rescuecd.iso. I've found docs that explain how to replace the 
packages but not the boot kernel. I've tried but I get a panic after the 
modules load.
Loading vmlinuz
Loading initrd.img
.. checks hardware
.. loads modules
Creating root device
umount /sys failed: 16
Mounting root filesystem
mount: error 6 mounting ext3
mount: error 2 mounting none
Switching to new root
switchroot: mount failed: 22
umount /initrd/dev failed: 2
Kernel panic - not syncing: Attempted to kill init!

Thanks
Richard Ray