[CentOS] fqdn hostname fails after reboot

Hi,

I have several machines running CentOS 6.2 and a strange problem with
the hostname of one machine... After every reboot it loses the fqdn
hostname.

Here is my confguration:

ifconfig | grep "inet addr"
          inet addr:10.0.0.12  Bcast:10.0.0.255  Mask:255.255.255.0
          inet addr:127.0.0.1  Mask:255.0.0.0

/etc/sysconfig/network

NETWORKING=yes
HOSTNAME=x800.mydomain.local
GATEWAY=10.0.0.1

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.0.0.12   x800.mydomain.local   x800

... after a reboot:

hostname
x800.mydomain.local             < OK

hostname -f
hostname: Unknown host       < NOT OK

dnsdomainname
dnsdomainname: Unknown host      < NOT OK

If I set the hostname manually:

hostname x800.mydomain.local

hostname -f
x800.mydomain.local    < OK

dnsdomainname
mydomain.local    < OK

Everything is okay ...

Something I've never experienced before. Does anyone have an idea?

thx

--
Chris