ZFS root failure after 9.2 -> 9.3 ugprade

[Patrick Gibson]

I just did a freebsd-update upgrade on a 9.2 system with zfsroot and now
when it boots, I get:

Booting from Hard Disk...
/
Can't find /boot/zfsloader

FreeBSD/x86 boot
Default: disk0:/boot/kernel/kernel
boot:
\
Can't find /boot/kernel/kernel

I've tried booting from a 9.3 install disc and going into the LiveCD and
reinstalling the bootloader with:

gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada0


Which says it's installed correctly, but still won't boot. Any advice would
be greatly appreciated.