I Cannot Install GRUB/LILO

I’m triple booting my iMac.

But after installing “GRUB/LILO”, I stilll need to insert the “DVD” to boot into either Win 7 or opensuse 11.3

Why is my install of the GRUB/LILO boot loader not working?

Thanks.

Error Message: No Bootable Device – Insert boot disk and press any key

I don’t know and I know nothing about iMacs, but did you install grub onto your disks master boot record (mbr) or a boot partition if they use these?

Maybe this link can help you.
GRUB Manual - Installation

Be very careful not to do anything to mess up your existing drive or installation.