GSATAII0/1 only detect SATA as IDE in BIOS

Am I glad I found this forum! this is confusing the hell out of me...

My issue is that I can't boot from a sata device on the onboard gigabyte sata controller. The board is a GA-EP35-DS4 rev2.1 (BIOS F3) it has a total of 8 sata ports - 6 x Intel Matrix RAID (southbridge) and 2 x Gigabyte (GSATAII0 & GSATAII1) - I have 4 drives in a RAID 5 array on the intel ports and a sata DVD + sata2 HDD that I want to run on the Giga ports (0 & 1).

I am reinstalling the OS and have decided to move the DVD and boot disk to the onboard sata controller (they were on the southbridge Intel controller for the last build) but I can't boot from either on this controller.

This is what I am seeing (or not...):
in the BIOS...

• the intel matrix is set up as RAID, this works fine
• onboard sata controller is enabled
• onboard sata mode is set to AHCI
• The HDD boot priority menu shows only the Intel_Raid + Add-on cards in the list
• IDE device detection shows nothing (they're not IDE so this is expected?)

There are no other IDE or SATA devices connected

If I change the mode to sata as IDE, both the DVD and sata HDD show up and can boot from, if mode set to RAID/IDE then nothing (not even the ctrl-G prompt in POST)

If I move either device to the intel controller they work fine as boot devices (detected as non-raid disks) - this was how I originally installed OS

If I move the HDD to intel and leave DVD on giga then windows boots and detects the DVD (but I still can't boot from DVD)

So, the controller and devices work fine, it's just the BIOS that won't see them. I have downloaded BIOS update F5 just in case but I'm paranoid about losing the data on the RAID array so would rather find another solution before flashing the BIOS.

Any help/insight greatly appreciated

Cheers,

Rich