Thanks for the quick reply.
Is this because it's already formatted with F and G partitions because the NFO file with the bios suggests the 4979.06 bios supports partitions >137gb:
"We have also integrated OzPaulb's fantastic LBA48 hack which we had to painstakingly convert from Assembly to C source. This is now embedded into our X2 source so you can use two versions of our bios.
One for LBA48 6 and one for LBA 48 6+7 (LBA48 6 is one large F partition - recommended for new HD installs, and LBA48 6+7 is for those who want to extend your current F drive to its larger size without losing any data). For those who don't know you were previously limited to a 137GB drive - now you can have up to 2 TB
(2199023255040 bytes) or 2000 Gb for the *ahem* uninformed."