Installing XP on S2696 fails very early on

Hi there; if anyone has assembled their own machine using the Tempest
i5000XT S2696, I would like to hear about any problems with installing
XP Pro, SP2.
The machine I built has two Xeon 5160, a Powercolor graphics card and
also an Adaptec 5405 RAID controller. To RAID controllerI have added
two Seagate Cheetah ST373455SS with no other drives attached. This
board version has no SCSI controller and only a SATA II controller; on
which I only added a DVD drive.

What I can do is initialize the drives and create a RAID 1 Mirror. I
can also use PowerQuest PartitionMagic to create a Primary Partition
within the RAID array.

But every attempt at installing XP Pro fails at the same point just
after the SAS driver is loaded after pressing F6 on the XP setup path;
shortly after XP reports some fatal error and advises it will shut
down.

Tyan have basically coped out on this, suggesting they do not have the
Adaptec controller at the lab; Adaptec have yet to answer my call for
help. Since I am running out of time on this issue, I wonder if anyone
out there has had similar problems; or a similar setup with not
problems.