[CentOS] onboard adaptec SAS RAID controller not seeing drive(s)

I have a Supermicro SuperServer 6025B-3V with their X7DB3 mobo. It has an onboard Adaptec SAS RAID controller and has been configured as a RAID1 with two Seagate Cheetah 15k.4 disks. Original attempts at installing CentOS4.4 x86_64 appeared to load the aic94xx driver, but then reported something like "No hard drives found...". I grabbed the x86_64 aacraid driver disk from Adaptec (updated 23 OCT 2006) and tried a "linux dd" install. Although the driver disk appears to load, I still get the "No hard drives found.." message.

I'm waiting for a response from Supermicro, but any advice from this list (including a controller that works) would be greatly appreciated.

Thanks, Steve Finley