[CentOS] Bind problem - rndc key (after update?)

Sat Nov 18 15:03:50 UTC 2006
kadafax <kadafax at gmail.com>

Hi list,

here is what happened:
today I noticed some resolution's problems on my network. I did a 
"service named status"  and here was the output:
# /etc/init.d/named status
rndc: connection to remote host closed
This may indicate that the remote server is using an older version of
the command protocol, this host is not authorized to connect,
or the key is invalid.

In the named's log, several entries like that:
general: error: invalid command from 127.0.0.1#42033: bad auth

I am not using the key's authentication on my chrooted bind dns and it 
was working great so far.

Searching on rndc's files in /etc I've found mismatch for the key value 
in /etc/rndc.conf and /etc/rndc.key. There was also a rndc.key.rpmnew file.
After giving the good value for the key entry (I've copied-pasted the 
value from the .key file), the bind daemon seems to be happy now.

My question is how things get broken because I didn't touch the bind's 
config files for a year or so (only the zone files, sometime) ?

---------------
CentOS 4.4 fully updated

[root at host etc]# rpm -qa | grep bind
ypbind-1.17.2-8
bind-libs-9.2.4-16.EL4
bind-utils-9.2.4-16.EL4
bind-chroot-9.2.4-16.EL4
bind-9.2.4-16.EL4

[root at host etc]# uname -a
Linux host 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 
x86_64 x86_64 GNU/Linux
-----------------

Thanks for any input.
Kfx