zfs auto snapshot (and thus time-slider) going offline after upgrade

The error will look something like this:

Checking for non-recursive missed // snapshots
Checking for recursive missed // snapshots rpool
Last snapshot for svc:/system/filesystem/zfs/auto-snapshot:frequent taken on Thu Nov 13 11:30 2008 which was greater than the 15 minutes schedule. Taking snapshot now. cannot create snapshot 'rpool/ROOT/opensolaris@zfs-auto-snap:frequent-2008-11-13-12:51': dataset is busy
no snapshots were created
Error: Unable to take recursive snapshots of rpool@zfs-auto-snap:frequent-2008-11-13-12:51.
Moving service svc:/system/filesystem/zfs/auto-snapshot:frequent to maintenance mode.

This problem is being caused by the old (IE: read non-active) boot environments not being mounted and it is trying to snapshot them. You can't 'svcadm clear' or 'svcadm enable' them because they will still fail.

Based on suggestions I find everywhere (most recently this one), I did this:
# mkdir /BE
# zfs list
(shows rpool/ROOT/opensolaris, rpool/ROOT/opensolaris-1 and the current rpool/ROOT/opensolaris-2)
# zfs set mountpoint=/BE/opensolaris rpool/ROOT/opensolaris
# zfs mount rpool/ROOT/opensolaris
# zfs unmount rpool/ROOT/opensolaris
(repeat the 3 steps for opensolaris-1)

Now you can run 'svcs -xv' to get the list of services and restart them... In my case:
# svcadm clear svc:/system/filesystem/zfs/auto-snapshot:frequent
# svcadm enable svc:/system/filesystem/zfs/auto-snapshot:frequent
# svcadm clear svc:/system/filesystem/zfs/auto-snapshot:hourly
# svcadm enable svc:/system/filesystem/zfs/auto-snapshot:hourly

Still have to test whether it works post-reboot without doing this every time.