How can I boot a 2012 Mac Mini off of a USB thumbdrive with CentOS on it? I have a 2012 Mac Mini running OS X 10.7.3. On another PC, I have created a USB boot disc with CentOS 6.2 on it. The goal was to install CentOS onto the Mini. The USB drive is MBR partitioned and boots fine on BIOS based PCs. However, not so on the Mac Mini. While holding down the option key, I see the USB drive offered as a "Windows Drive" however selecting it to boot into causes the screen to go completely black and the words "Boot Error" to be displayed with a blinking cursor underneath the words.

I have installed rEFIt as an EFI boot manager onto the Mac Mini. Using the rEFIt boot management screen to select the USB drive to boot from causes no difference. The Mini can boot from a USB drive that I turned into an Apple Recovery Disk.

What could be preventing the Mac Mini from booting off of the USB drive when other BIOS based PCs don't have trouble with it?
It appears that the Mac Mini version that I purchased cannot, as of the time of this post, accept an alternate operating system. Hacks and workarounds may exist, but they are not apparent.