Weird Issue with DL 360p G8 Array Controiler. ^GCaution: invalid main GPT Header

[CitrixGuy]

I had a new Proliant DL360p G8 Server setup with the internal array controller and no cache.  It had five 450GB SAS Drives in it.  I installed XenServer 6.1 onto it with no issues.  I wanted to user RAID5 so I bought a 2GB Cache Module.  I put it into the server, ran the ACU deleted my existing Logical Drive and created a new Logical Drive with RAID5.  I then popped in the XenServer 6.1 CD and Tried the install again.  This time I got an unrecoverable error related to CRC Errors and GPT headers.  Same issue can be seen here:

http://vikashkumarroy.blogspot.in/2012/03/error-partition-table-could-be-written.html

If I disabled GPT and user MBR the install works fine.

I contacted Citrix Support and they sent me here and said I should ask the Linux Folks if there are any known issues with the Array Controllers, etc.  I'd love to know if anyone has any insight on this topic?  For example, why did it work with no cache and a stripe set?  What did adding the Cache and RAID5 Change?  Or is my issue due to XenServer having put some data on the Controller that is still there and being detected despite wiping out and recreating my Logical Drives?

Thanks for the support!