Thom -
You mention you're using the latest version of the Host Utilities Kit.
There's a known bug with the mbralign tool in the 5.2 HUK, you want to use the one included with the 5.1 version of the HUK.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff
ekashp@kashpureff.org
Senior Systems Architect / NetApp Certified Instructor
http://www.linkedin.com/in/eugenekashpureff
(P.S. I appreciate points for helpful or correct answers.)