Static Leases do not work

["Küppers, Malte"]

authorative;
ddns-update-style none;

lease-file-name "/var/lib/dhcpd/dhcpd.leases";
max-lease-time 200;
default-lease-time 100;

omapi-port 9991;
key omapi_key {
algorithm HMAC-MD5;
secret  <removed> ;
};
omapi-key omapi_key;

  subnet 10.159.3.0 netmask 255.255.255.0
   {
     authorative;
       range 10.159.3.89 10.159.3.188 ;
       ignore client-updates;
       option subnet-mask 255.255.255.0;
       option domain-name "mydomain.de";
       option domain-name-servers 172.16.111.10, 172.16.111.20;
       option routers 10.159.3.2;
       option ntp-servers 172.128.194.5;
       vendor-option-space innovaphone;
       option innovaphone.h323-gatekeeper 172.128.194.5 ;
       option innovaphone.tos-bits "0x10" ;
       option innovaphone.update-poll-interval 0x5A0;
       option innovaphone.update-url "http://172.116.113.207/V6/ 000-049_Phones.txt";
       option innovaphone.local-networks "10.159.3.0:255.255.255.0" ;
  }

This is a sample subnet. There are multiple 1000 similar ones. Maybe the problem is connected to a hourly restart of dhcpd? The config is dynamically created by script every hour, what maybe
causes the wipeout? When I set the reserved flag I can see it in the leases file, but as I said it gets lost... It's not a special host, just a bunch of laptops I use for testing. But regardless of the host,
the lease should stay in the leases file even after some restarts and host downtime? 
Maybe I should spilt the range and use host statements via omapi... I just have to make sure static leases don't get lost since that would really be disastrous.

Regards