Newbie and DHCP no free leases

Can anyone spot my mistake in this dhcp configuration.

I am continually getting the error "no free leases" when I try
to do any class matching.

In the configuration file you can see I have tried a number of ways
to match a client. I have tried a simple hardware match but that
failed.

Can anyone say why the subclass ethernet address has a 1: prepended
to it. I have tried it with and without this of course!

The configuration file follows:

ddns-update-style ad-hoc;
default-lease-time 21600;
max-lease-time 43200;
option domain-name-servers 10.0.0.138;

subnet 10.0.0.0 netmask 255.192.0.0 {
#not authoritative;
option broadcast-address 10.0.0.255;
option routers 10.0.0.138;
range 10.0.0.11 10.0.0.254;
}


class "admin" {
#match pick-first-value (option dhcp-client-identifier, hardware);
match if substring ( option host-name, 1, 10) = "officepcyc";
}

class "training" {
match if substring ( option host-name, 1, 12 ) = "trainingpcyc";
#match pick-first-value (option dhcp-client-identifier, hardware);
#match hardware;
}

subclass "training" 00:0c:6e:f8:5b:d4;
subclass "training" 1:0:c:6e:f8:5b:d4;
subclass "training" 1:00:0c:6e:f8:5b:d4;

group {
use-host-decl-names on;

host trainingpcyc1 {
hardware ethernet 00:0c:6e:f8:5b:d4;
#fixed-address 10.128.0.2;
}
}

class "NetCafe-Clients" {
match pick-first-value (option dhcp-client-identifier, hardware);
#match if substring ( option host-name, 1, 7) = "netcafe";
}

shared-network pcycnet {
subnet 10.64.0.0 netmask 255.192.0.0 {
option routers 10.64.0.10;
pool {
allow members of "Admin-Clients";
deny unknown clients;
range 10.64.0.11 10.64.0.254;
}
}

subnet 10.128.0.0 netmask 255.192.0.0 {
option routers 10.128.0.10;
pool {
allow members of "training";
deny unknown clients;
range 10.128.0.11 10.128.0.254;
}
}

subnet 10.192.0.0 netmask 255.192.0.0 {
option routers 10.192.0.10;
pool {
allow members of "NetCafe-Clients";
deny unknown clients;
range 10.192.0.11 10.192.0.254;
}
}
}

----------------

The error message seen is:

DHCPDISCOVER from 00:0c:6e:f8:5b:d4 via eth1: network pcycnet: no free leases
DHCPDISCOVER from 00:0c:6e:f8:5b:d4 via eth1: network pcycnet: no free leases