Exchange 2010 DAG failover isn't working as I thought.

I know I am missing something, my guess is the CAS array.  Any input would be very grateful.

My environment is

Site A North Carolina:

EXCASNC 10.1.10.100/20
Windows 2008 R2 Ent
CAS and HubTransport

EXMBNC 10.1.10.105/20
Windows 2008 R2 Ent
Mail Store DAG
5 Mail stores on 5 different Drives

Site B California:

EXCASTX 10.50.10.100/20
Windows 2008 R2 Ent
CAS and Hub Transport

EXMBNC 10.50.10.105/20
Windows 2008 R2 Ent
Fail Over Mail Store

I have the DAG setup and it is copying over the Mail stores from EXMBNC and the Mail stores are healthy. When I did the fail over test my Outlook client couldn't connect even though the EXMBTX Mail Store states it is mounted. My means of testing right now is to just shut down the EXMBNC and not the EXCASNC.  I will work on the CAS redundancy after I get some help on this snag.

Thanks
-C