VIA 6420 SATA150 controller on FreeBSD 6.0

Hi,

I created a raid-1 with 2 SATA disks with the controller VIA 6420
SATA150 from the bios setup.
FreeBSD detects the array with ar0 and I can use /dev/ar0s1 to mount
my data on FreeBSD 6.0-BETA4.

atapci0: <VIA 6420 SATA150 controller> port
0x9000-0x9007,0x9400-0x9403,0x9800-0x9807,0x9c00-0x9c03,0xa000-0xa00f,0xa400-0xa4ff
irq 20 at device 15.0 on pci0
ata2: <ATA channel 0> on atapci0
ata3: <ATA channel 1> on atapci0
[...]
ad4: 194481MB <Maxtor 6L200M0 BANC1G10> at ata2-master SATA150
ad6: 194481MB <Maxtor 6L200M0 BANC1G10> at ata3-master SATA150
ar0: 194480MB <VIA Tech V-RAID RAID1> status: READY
ar0: disk0 READY (master) using ad4 at ata2-master
ar0: disk1 READY (mirror) using ad6 at ata3-master

%mount | grep ar0s1
/dev/ar0s1 on /raid (ufs, local, soft-updates)

%df -h | grep ar0s1
/dev/ar0s1             184G     54G    115G    32%    /raid

If I remove one of the disks, FreeBSD can't mount /dev/ar0s1 and I see
these errors:

ad4: 194481MB <Maxtor 6L200M0 BANC1G10> at ata2-master SATA150
ar0: 194480MB <VIA Tech V-RAID RAID1> status: BROKEN
ar0: disk0 DOWN no device found for this subdisk
ar0: disk1 DOWN no device found for this subdisk

and
# ls /dev/ar*
/dev/ar0

AFAIK, if one disk fails, I can continue to use the raid-1 and mount
ar0s1 (corret me, if I'm wrong).

How can I solve this problem?
dmesg is attached.

Thanks for your help.

Let me know if you need more information.

Regards
-- 
There's this old saying: "Give a man a fish, feed him for a day. Teach
a man to fish, feed him for life."