Solaris 11 Express update versions reported during update versus uname -v

Hello,
Could you, please, explain why the reported global zone (update) version is reported 151.0.1.11 by IPS but 151.0.1.8 by uname -v ?

s11-01:~ # uname -v
151.0.1.8

s11-01:~ # zoneadm list -cv
  ID NAME             STATUS     PATH                           BRAND    IP   
   0 global           running    /                              ipkg     shared
   - s11-z6a          installed  /zones/s11-z6a                 ipkg     excl 
   - s11-z6b          installed  /zones/s11-z6b                 ipkg     excl 

s11-01:~ # zoneadm -z s11-z6a detach
s11-01:~ # zoneadm -z s11-z6a attach -u
Log File: /var/tmp/s11-z6a.attach_log.Ngaa6b
Attaching...

preferred global publisher: solaris
       Global zone version: entire@0.5.11,5.11-0.151.0.1.11:20110906T215354Z