My guess would be the boot manager not know where to look or how to load the initrd from FC. I'm not familiar with BootMagic, so I really can't tell you what to do other than to make sure it is pointing to the /boot partition. I imagine you'll still have to GRUB to boot FC. Did you setup GRUB on your /boot partition (e.g. `grub-install /dev/hda4`)?
--JamesT
