refresh timeouts

[tsar.peter at gmail.com]

It could be a problem with som "iptables" filters blocking traffic,
at master or client side. Do some tcpdumps to find out
what is going on, both at server and client side at the time of
failure.

Also i would recommend removing the :
    query-source address * port 53;
        transfer-source * port 53;
        notify-source * port 53;
the adds nothing but confusion.
The use of forwarding ; are you shure you really want it ? At most
installations it only adds unavailability and longer delays. Remove.

Finally, for your security, allow recursion for your hosts only. There
is 
no point in you serving Internet with resolving resources.