bind: master file not found

[schudi]

hi there,

i've got a problem with bind.

now i get this message for every domain on the server:

Feb  4 08:00:26 {host} named[4954]: zone {domain}/IN: loading master file {domain}: file not found

but, nothing has changed! no program installed, no configuration change...

after i added this

options {
        directory "/var/lib/named/var";
};

to the /etc/named.conf it works again.

why has plesk changed the configuration? and how to prevent this in future? when i add a new domain, the /etc/named.conf is rewritten and the directory-option is deleted...

i hope anyone can help!

greetz
michael