ESXi 5.0 and MSCS (Microsoft Failover Clustering) on iSCSI SAN

I have spent the past week trying to get my test lab up and running to do a proof of concept for MSCS (Microsoft Failover Clustering) on an iSCSI SAN.  However I have hit a brick wall and desperately need some help.

My test lab consists of the following:

1. 2 VM's running on the same ESXI 5.0 host.
2. The virtual machines are running Windows Server 2008 R2 with SP1.
3. On the VM's the system disk has been configured to use Thick Provision Eager Zeroed which is required on the VMFS.
4. For the shared storage I am using RDM on the ISCSI SAN.

On the VM's, at the file system level I can see the shared storage which is offline, as expected, but when running the MSCS Validation Checker it isn't able to find any disks which can be used for the shared storage.

I have read tons of documentation but can get past this sticking point.

For reference here are 2 articles which say it can be done on an iSCSI SAN.

http://communities.vmware.com/thread/394367?start=0&tstart=0

http://communities.vmware.com/thread/258403?start=0&tstart=0

I have also read these VMware guides:

VMware KB:    Microsoft Clustering on VMware vSphere: Guidelines for Supported Configurations 

http://pubs.vmware.com/vsphere-51/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-51-setup-mscs.pdf

I have read MSCS is not supported on a iSCSI SAN, but should be workable using Raw Device Mappings (RDM).

Any suggestions?