Should the bios update not resolve the problem, Try it in a sata 2 port which is where I would have put it naturally.
Failing that try the marvell ports. Those can be set to ide mode independently from the intel ahci mode.
Doh - when I said Sata 3 i meant SATA 3gbs which is Sata2 (Doh!) - sorry.
I have tried the new drive in both SATA 2 (3gbps) and SATA 3 (6gbs) ports just in case... what really bugs me is that if I disconnect the LG drive, everything else and my Samsung SH-222AL DVD Combo work fine in AHCI mode..
The Marvell controller on my board 'Does not support ATAPI devices' and cannot be used as the boot drive.... according to the User Guide, but I will give it a go.