The usual way to set up multiple Linux distros (as far as the bootloader goes) is to:
1) decide which distribution's bootloader you actually want to see when you boot;
2) install the other distro, installing its bootloader to the distribution's / partition rather than the MBR (you won't be able to boot this distro until the "main" bootloader is installed. Afaik, you can install either bootloader-- it doesn't
have to be the same as the 'main' bootloader, but since most distros allow you to choose, I usually install the same one as the 'main' distro's bootloader to minimize problems);
3) install the 'main' distro, installing its bootloader to the MBR;
4) boot into the 'main' distro, load up the bootloader's config file and configure the second distribution to be booted from the main bootloader menu.
For example, I have both Gentoo and SuSE on my disk, and here's my grub.conf:
Code:
title Gentoo_current (2.6.11-gentoo-r11)
root (hd0,1)
kernel /vmlinuz ro root=/dev/hda5 video=vesafb-tng:ywrap,mtrr,pmipal,1280x1024-32@60 splash=silent,theme:emergence quiet CONSOLE=/dev/tty1
initrd /fbsplash-emergence-2611-11
title Gentoo_prev (2.6.11-gentoo-r8)
root (hd0,1)
kernel /vmlinuz-2.6.11-gentoo-r6 ro root=/dev/hda5 video=vesafb-tng:ywrap,mtrr,1280x1024-32@60 splash=verbose,theme:emergence quiet
initrd /fbsplash-emergence-1280x1024
title SUSE LINUX 9.3
root (hd0,1)
kernel /vmlinuz-2.6.11.4-20a-default real_root=/dev/hda6 vga=0x317 selinux=0 splash=silent resume=/dev/hda6 showopts
initrd /initrd-2.6.11.4-20a-default
It's really pretty much that simple, except that I use a boot partition, so all the kernels are in the same place. If you don't, I think you have to either configure the bootloader so that it knows where the 'foreign' kernel is, or copy the kernel and subsidiary files to the /boot location of the 'main' bootloader, but it's been a while since I had to do anything like that, so I'm hazy on the details. Also, SuSE in particular is very complex and picky (probably because of the initrd), so I literally copied the bootloader information from SuSE's bootloader config to the one I was using, but other distributions can boot from a much simpler configuration.
This link might help you (I guess you're using LiLO):
Litt's Lilo Lessons, which basically says the same thing, except more LiLO-specific, and also Litt seems to prefer to install the 'best' distro first, whereas I prefer to do it last. But that's just preference; I think you can do it either way around and as long as you hit all the steps, you should be good to go.
You might also try
Multiboot Lilo
and
The Lilo Bootloader
Hope this helps, and good luck.