gptzfsboot and 4k sector raidz

[Daniel Mayfield]

I just set this up on an Athlon64 machine I have w/ 4 WD EARS 2TB disks.  I followed the instructions here: http://www.leidinger.net/blog/2011/05/03/another-root-on-zfs-howto-optimized-for-4k-sector-drives/, but just building a single pool so three partitions per disk (boot, swap and zfs).  I'm using the mfsBSD image to do the boot code.  When I reboot to actually come up from ZFS, the loader spins for half a second and then the machine reboots.  I've seen a number of bug reports on gptzfsboot and 4k sector pools, but I never saw one fail so early.  What data would the ZFS people need to help fix this?

daniel