I have the latest BIOS (0099).
I have two bootable hard drives connected. The BIOS always boots from the drive plugged into the lowest numbered SATA port, regardless of the boot order I specified in the BIOS. I have one drive connected to SATA port 1 and the other connected to SATA port 3. It always boots from the one connected to SATA port 1. I have swapped the drives and it still boots from the one connected to SATA port 1.
If I should hit F10 while the BIOS is running, it displays the drives on the boot device list in the correct order as specified in the boot order list. The one at the top of the boot order list is on top, and it is highlighted. So if I just hit enter it will boot from the correct one. But if I don't hit F10 it will boot from SATA port 1.