P-965 Neo F V.2 - Can't boot from DVD drive

Hi!

I have an IDE DVD Drive, and a SATA disk.

I've connected de SATA disk to the purple SATA connectors (not the blue one).

The IDE on the onboard IDE.

I can't boot from ANY DVD. I get a blank screen with the cursor flashing (in text mode).

Tested:
- The DVD Drive on another machine: Boots fine.
- Many boot cd's (windows xp, hiren's boot cd, etc).
- Another drive, a CD drive, same problem.

I know it worked some time ago, but never changed. I know it because I installed Windows XP with the boot cd.

Any help?