How to custom rescue disk

[Richard Ray]

I've been trying to add a new vmlinuz and initrd.img to isolinux on the 
FC3 rescue disk. The new cd boots and loads vmlinuz and initrd.img but 
panics when it starts to mount the file systems. I've found several 
references on the net about how to customize the packages on a boot disk 
but not how to replace the boot kernel. Please direct me if this is 
not the correct list for this.

Thanks
Richard Ray