Problem with shared-network

[robert at spotswood-computer.net]

I have a Debian 7.0 running isc-dhcp-server 4.2.2.

My server has a single NIC, and using iproute, I've added additional
addresses (some lines snipped for brevity):

eth0      Link encap:Ethernet  HWaddr 00:50:56:XX:XX:XX
          inet addr:192.168.220.111  Bcast:192.168.220.255 
Mask:255.255.255.0

eth0:1    Link encap:Ethernet  HWaddr 00:50:56:XX:XX:XX
          inet addr:10.111.111.1  Bcast:10.255.255.255  Mask:255.255.255.0

My goal is for the dhcp server to hand out unknown clients addresses from
the 10.111.111.X pool, and known client to get something from the
192.168.220.X pool. Since these are on the same subnet, I [believe] this
requires a shared-network block. My dhcpd.conf file looks like (with
comments and global options stripped out for brevity):

shared-network my-net {
        subnet 192.168.200.0 netmask 255.255.255.0 {
                range 192.168.200.194 192.168.200.200;
                range 192.168.200.215 192.168.200.250;

                ignore unknown-clients;
  <bunch of options removed>
        } #subnet 192.168.200.0

        subnet 10.111.111.0 netmask 255.255.255.0 {
                range 10.111.111.5 10.111.111.200;
                allow unknown-clients;
<bunch of options removed>
        } #subnet 10.111.111.0
} #shared-network

It runs, but only gives out 192 addresses. If I reverse the order, so the
10 subnet declaration comes first, then it hands out 10 addresses, but not
192 addresses.

Any ideas what I am doing wrong?