From SME Server
The Apple MacMini (Intel) is a very energy efficient hardware-platform and uses the new Intel EFI technology as bootprom, which is not compatible with the standard grub boot-loader. So no standard Linux distribution would start on the MacMini. You have to replace grub with the older lilo bootloader.
With this Howto you can install SME Server on the MacMini (Intel) which uses EFI based bootprom without support for the grub standard