[syslog-ng] Umask funkiness

[Declan White]

I have a directory owned by the syslog-ng user. Its group however belongs to a group of which the user is not a member.
The directory is g+s, so that all files and dirs made within it inherit the group owner (and the g+s in the case of dirs).

syslog-ng is running with a umask of 022 (interrogated running process to be sure). 
The file("/dir/${FOO}/${BAR}") destination driver has :
                create-dirs(yes) 
                perm()
                dir-owner()
                dir-group()
                dir-perm()
i.e. "don't change any perms"

The aim of the game is to end up with files and dirs readable, but not writable, by the inherited group owner.
I can't get it working. I am always ending up with 
drwx--S--- dirs and 
-rw------- files

Solaris. syslog-ng-3.12.1

-- 
Declan White