We found a workaround for the zone issue. Now it boots (or doesn't) with the following messages:
Rebooting with command: boot
Boot device: /pci at 1f,4000/scsi at 3/disk at 9,0:a File and args:
SunOS Release 5.10 Version Generic 64-bit
Copyright 1983-2005 Sun Microsystems, Inc. All rights reserved.
Use is subject to license terms.
Nov 21 14:04:36 svc.startd[7]: svc:/network/loopback:default: Method
"/lib/svc/method/net-loopback" failed with exit status 1.
Nov 21 14:04:37 svc.startd[7]: svc:/network/loopback:default: Method
"/lib/svc/method/net-loopback" failed with exit status 1.
Nov 21 14:04:37 svc.startd[7]: svc:/network/loopback:default: Method
"/lib/svc/method/net-loopback" failed with exit status 1.
[ network/loopback:default failed (see 'svcs -x' for details) ]
Nov 21 14:04:38 svc.startd[7]: svc:/network/physical:default: Method
"/lib/svc/method/net-physical" failed with exit status 1.
Nov 21 14:04:38 svc.startd[7]: svc:/network/physical:default: Method
"/lib/svc/method/net-physical" failed with exit status 1.
Nov 21 14:04:39 svc.startd[7]: svc:/network/physical:default: Method
"/lib/svc/method/net-physical" failed with exit status 1.
[ network/physical:default failed (see 'svcs -x' for details) ]
Nov 21 14:04:41 svc.startd[7]: svc:/system/device/local:default: Method
"/lib/svc/method/devices-local" failed with exit status 1.
Nov 21 14:04:42 svc.startd[7]: svc:/system/device/local:default: Method
"/lib/svc/method/devices-local" failed with exit status 1.
Nov 21 14:04:42 svc.startd[7]: svc:/system/device/local:default: Method
"/lib/svc/method/devices-local" failed with exit status 1.
[ system/device/local:default failed (see 'svcs -x' for details) ]
Nov 21 14:04:43 svc.startd[7]: svc:/network/service:default: Method
"/lib/svc/method/net-svc start" failed with exit status 1.
Requesting System Maintenance Mode
(See /lib/svc/share/README for more information.)
Console login service(s) cannot run
The /etc/svc/volatile logs contain info like this:
executing start method ("/lib/svc/method/net-loopback")
Timeout override by svc.startd. Using infinite timeout
/lib/svc/method/net-loopback: test: argument expected
Method "start" exited with Status 1
Help!