RAID10 doen't boot

[Indiana Jones]

Hi,
I'd really appreciate it if somebody could help me out!
I have a box with a MB ASUS P5WDG2-WS Pro with two built-in SATA II RAID controllers 
(Intel ICH7R and Marvell 88SE614x).
I installed 4 HDD WD WD5002ABYS (500GB each) on the 4 SATA ports of the Intel 
ICH7R and using the Intel Matrix Storage Manager I created a RAID10 (Strip 14KB, Size 
931.5GB, Status Normal, Bootable Yes) out of these 4 HDD.
Then in the BIOS I set the IDE Configuration to Configure SATA As [RAID], OnBoard 
Serial-ATA BOOTROM [Enabled] and disable the Marvell SATA controller, for I use only 
the Intel ICH7R.
 Then I successfully installed FreeBSD 7.1 on the RAID partition, ar0.
 
The installation completed successfully but the system persistently didn't boot and gave this 
error message:
 
F1    FreeBSD Default: F1 No /boot/loader FreeBSD/i386 boot Default: 0:ad
(0,a)/boot/kernel/kernel boot: No /boot/kernel/kernel

Thanks a lot,
Alex