SAS Disks not being detected in R7910 Workstation

Hi, we recently purchased a set of 1.8TB 10k 2.5" SAS disks for one of our R7910 Precision Workstations (per advice from our Dell representative).  However, these disks are not being properly detected by the system upon power-up.  I am using the latest 2.2.4 BIOS of the system.  These disks are populating six of the eight available disk slots at the front of the system.  Has anyone else been able to get these disks working in their R7910?

Thanks, Kevin