gmirror unable to boot kernel from second disk

[dave]

Hello,
    I posted this to -questions but haven't got a response. I'm following
procedure2 of the gmirror for system disks howto at:

http://people.freebsd.org/~rse/mirror/

and i get to the first reboot stage. The box never comes back up. I have to
plug in a monitor to it as i do everything via ssh and it says that it can't
find the kernel. This is using the stage2 boot loader on the first disk to
boot stage3 off the second disk in preparation for sync-ing the two disks
and bringing up the raid. This is on a 5.4-stable box cvsupped as of last
week. This is my third atempt at raid1 on this box, on another box this
procedure went fine, it's also running -stable. Before i rebooted the box i
checked /mnt/boot/kernel and there was indeed a kernel file in that
location. Up until the first reboot i didn't get any errors, or warnings,
and the procedure went fine.
Any help appreciated.
Thanks.
Dave.