Solaris NSS problem, only seeing few winbind groups

[ww m-pubsyssamba]

I'm having a strange problem with winbind. For users it seems to be working fine but for groups its not enumerating most of the groups!
A getent group produces only 325 lines of domain groups whereas wbinfo -g produces 2839 lines of groups. I'm not seeing any errors 
logged and all commands are exiting with status 0. 
Winbind related sections of smb.conf are shown below,

	security = ads
	   encrypt passwords = yes
	             winbind separator = +
	             winbind cache time = 300
	             winbind use default domain = Yes
	             template shell = /bin/sh
	             template homedir = /tmp
	             idmap uid = 10000-600000
	             idmap gid = 10000-600000
	        winbind enum groups = yes
	        winbind enum users = yes
        allow trusted domains = no


I don't know where to start for debugging an nss related problem, are there any logs/daemons etc. I can check or turn debugging on?
There is a bugzilla bug, no. 1030, which appears to be the same problem, but there is no actoins/activity logged against is except for me.

Any help much appreciated,

		thanks Andy.