Adding groups to /Local/Default

I've added a network group ("deploy") to the local computer Admin group using the cmd:

$ dseditgroup -o edit -u <localadmin> -P <pass> -a deploy -t group admin

I verify it's (the GUID) listed under "NestedGroups" with:

$ dseditgroup -o read -n /Local/Default admin

However, when I try to do something simple, like unlock the system prefs "lock" with a Network User who is a member of that Network Group "Deploy", it doesn't recognize it as valid.

What am I doing wrong?

OSX 10.6.8 clients and server