Same problem, update fails. I'm also unlocked, rooted, and I had OTA Voodoo activated. After the first time it failed, it went into a reboot/power off cycle. Every time the phone rebooted and was completely started, it would power off. I cleared the cache and that fixed the reboot. I'm back running normally with the update waiting to be downloaded and install.
I also have CWM recovery, wounder it that is why my updated failed but MBSMD worked?
JohnT