[CentOS] Question about dhcpd.leases

Hi,

I'm running a DHCP server on my local network. I've noticed something 
that puzzles me. Leases are written to /var/lib/dhcpd/dhcpd.leases, but 
only - so it seems to me - if the address is not fixed in any way in 
dhcpd.conf.

Here's a few stanzas of my dhcpd.conf :

host babasse    {
         hardware ethernet 00:0d:61:ae:6b:8f;
         fixed-address 192.168.1.1;
         option host-name "babasse";
}

host bernadette {
   hardware ethernet 00:0d:61:a6:e7:1e;
   fixed-address 192.168.1.2;
   option host-name "bernadette";
}

host raymonde {
   hardware ethernet 00:20:ed:b8:e8:ec;
   fixed-address 192.168.1.3;
   option host-name "raymonde";
}

host lifebook {
         hardware ethernet 00:0b:5d:46:f2:10;
         fixed-address 192.168.1.5;
         option host-name "lifebook";
}

How comes these machines never appear in dhcpd.leases ? Do the 
respective leases only find their way into /var/log/messages ?

Cheers,

Niki