root-on-ZFS - gptzfsboot fails to find pool

[Elliot Robinson]

G'day all,
A fresh root-on-ZFS install using bsdinstall's ZFS option on FreeBSD 10
fails to boot on my Dell Studio XPS 1640. Output at boot is

gptzfsboot: error 1 lba 48
gptzfsboot: error 1 lba 1
gptzfsboot: No ZFS pools located, can't boot

Things I've tried:
  * ZFS with GPT - Fails with error above
  * ZFS with MBR - Fails with no output (doesn't find 2nd stage?)
  * UFS with GPT - Works
  * Different HDD/SDD - No change, fails with error above
  * USB thumb drive on VirtualBox with ZFS/GPT - Works

This system has not had FreeBSD on it before, though the guided
partitioning UFS/GPT install seems to work as expected.

I'm about at the point where I have to sprinkle printf's all through
zfsboot.c and trace what's going on, so any help is appreciated.

---
Elliot Robinson
PGP Key: 9FEDE59A