I emailed Stephen over at Xen/Citrix about the issue and this is what he sent back:
You must have ESP... I was just thinking about this! I had to can my current project and use something else as I just couldn't make any headway! I am only left with two small issues in 3.2 where I cant get the pciback working or a simple bridge setup :(
I wonder what happened...
Thanks for the update! jlc