Class matching not working

[Greaser, Tom]

Who out there can give me a good kick..  as im hitting my head against this and dont see why..

Im trying to get a class + pool statement to work.
Server is running  ISC 4.1.0,    below is a config snippet

My issue seems to be, I must not be matching the right thing as dhcp logs shows
  dhcpd: DHCPDISCOVER from 00:1f:16:21:1c:7a via 10.3.66.1: unknown client


#A stipped down config Global#
server-identifier smack.test.edu;
option domain-name "test.edu";
default-lease-time 43200; # 12 hours
max-lease-time 43220; # 12 hours 2min

boot-unknown-clients false;
use-host-decl-names true;
option ieee802-3-encapsulation false;
option router-discovery false;

log-facility local1;
option option-150 code 150 = array of ip-address;
option ip-forwarding false;

deny duplicates;
deny bootp;




class "simlab" {
        match pick-first-value (option dhcp-client-identifier, hardware);
       }
        subclass "simlab" 1:0:1f:16:21:1c:74;
        subclass "simlab" 01:00:1f:16:21:1c:7a;



group {
#private ip address ranges
#... more options 
#bunch of subnets..

subnet 10.3.66.0 netmask 255.255.255.0 {
        pool {
        range 10.3.66.10 10.3.66.254;
        allow members of "simlab";
        }
        option routers 10.3.66.1;
        default-lease-time 600; #10 min lease
        option domain-name-servers 10.10.10.8, 10.10.182.
}




Thanks,
Tom