Following on the footsteps of older bugs coming back to bite us. I have found an issue with Citrix Provisioning Services 6.1 Update 19 on Windows 2008 R2 (this does not affect Windows 2008 x86).
Issue: Citrix Provisioning Server 6.x displays Blue Screen of Death (BSoD) when starting target Virtual Machine from the vDisk. When starting the target Virtual Machine from the vDisk, this BSoD (0x0000007b) is displayed, while the master Virtual Machine did not have any problems.
Note: Do NOT install the Device Identity Manager software if you are running Provisioning Services 6.0 software or later. The latest version of Device Identity Manager was included in the 6.0 target device software going forward. Installing Device Identity Manager atop any 6.0 or later target device software breaks the network interface and prevents XenConvert from running.
But this article was exactly what the doctor ordered, Eureka!!, I was almost ready to rebuild the image from scratch as everything else worked correctly.
Resolution: Apply Microsoft KB article 2550979 Updated 10/10/2013 New link to support 2008 R2 SP1 and RTM patch
I recommend going through the other steps for troubleshooting first but I hope this helps you resolve this issue in the future.