I recently upgraded to Fedora 16 on my desktop PC, and had the unpleasant experience – which I can’t remember having for many years on Linux – that after a successful installation, it simply failed to boot. I was pretty surprised, but the Fedora common bugs page has an entry “Some systems…cannot boot GPT labelled disks“. Although it doesn’t mention Intel motherboards, this does seem to apply to mine, since the workaround described – marking the protective MBR entry as active – did work, and allowed the system to boot.
Anyway, maybe someone else will find this useful. There is a D975XBX2 BIOS update available (my machine was using revision 2770, some revisions back from the latet) so I guess I’ll try that sometime and see if it fixes the problem, although there is nothing obvious in the BIOS release changelog about it.