6.0-BETA5: Sees only first ATA RAID volume

Hi *,

Doing some experiments on a Dell Precision 380 with ICH7 (Intel
MatrixRAID) SATA RAID controller. There are three 160 Gb SATA disks
in the machine. 

In the BIOS, I configured two RAID volumes:
  * one mirror (RAID1) with a capacity of 110 Gb, involving the
    first two disks (leaving 50 Gb of free space on each disk);
  * one striped (RAID0) using the remainder of the space of each
    of the first two disks.

(the 3rd disk is completely outside of the RAID system).

When booting up, I see the three physical disks as ad4, ad6, and ad8, 
buth only the first RAID volume as ar0 (with a disk size that looks like
the expected 110 Gb) - I do not see any ar1 striped volume.

Is this a bug? A known limitation? Anything specific I need to set up?

Thanks!
Thomas.