FreeBSD 9.1 won't boot with a graid error

[F. Senault]

Hi everybody.

I've just upgraded a box from FreeBSD 9 to 9.1 via freebsd-update.

At the first reboot, the machine stopped with messages about GRAID :

GEOM_RAID: Promise: Subdisk kjihgfedcba`_^]\[ZYXWVUTSRQPONM:0-ada0 state
changed from NONE to ACTIVE

The trick is that I've never setup any kind of RAID on that old box...

Is there a way to completely disable GEOM_RAID loading on boot ?

Here are the obligatory blurry-cellphone-pictures of the boot messages :

https://www.dropbox.com/s/wqgjsf1adhoaksb/boot1.jpg
https://www.dropbox.com/s/99z1cojz22w7jn4/boot2.jpg
https://www.dropbox.com/s/7hk1inrhd1k59zi/boot3.jpg

The motherboard is an old GA-8IG100MK, fitted with two supplementary
3com NICs.

The specs can be found here :

http://www.gigabyte.com/products/product-page.aspx?pid=1655#sp

Chipset :
  - North Bridge : Intel® 865G GMCH
  - Intel® 82801EB
  - Intel® 82562EZ Ethernet Controller
  - Super I/O: ITE I/O IT8712F chip
  - Realtek ALC655 CODEC
  - 3M bit flash ROM

TIA,

Fred