DNS queries are timeout using bind in RHEL 5

I am having Red Hat Enterprise Linux Server release 5.11 with bind-9.3.6-25.P1.el5_11.12 installed , We have DNS service running on RHEL5 for domain resolution and we found multiple times nslookup was getting timed out from client , the bind named.conf was configured and it was working fine almost 5 years

Now removing below from named conf file has resolved the issue

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
        channel my_file {
                 file "data/log.msgs";
                  severity dynamic;
        };
        channel my_syslog {
                 syslog daemon;
                 print-time no;
                 print-severity no;
                 print-category no;
        };

** I am still not able to find how the issue resolved by removing above line from logging and adding below to the logging **

channel default_file {
        file "/var/log/named/default.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel general_file {
        file "/var/log/named/general.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel database_file {
        file "/var/log/named/database.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel security_file {
        file "/var/log/named/security.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel config_file {
        file "/var/log/named/config.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel resolver_file {
        file "/var/log/named/resolver.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-in_file {
        file "/var/log/named/xfer-in.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-out_file {
        file "/var/log/named/xfer-out.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel notify_file {
        file "/var/log/named/notify.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel client_file {
        file "/var/log/named/client.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel unmatched_file {
        file "/var/log/named/unmatched.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel queries_file {
        file "/var/log/named/queries.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel network_file {
        file "/var/log/named/network.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel update_file {
        file "/var/log/named/update.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dispatch_file {
        file "/var/log/named/dispatch.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dnssec_file {
        file "/var/log/named/dnssec.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel lame-servers_file {
        file "/var/log/named/lame-servers.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    category default { default_file; };
    category general { general_file; };
    category database { database_file; };
    category security { security_file; };
    category config { config_file; };
    category resolver { resolver_file; };
    category xfer-in { xfer-in_file; };
    category xfer-out { xfer-out_file; };
    category notify { notify_file; };
    category client { client_file; };
    category unmatched { unmatched_file; };
    category queries { queries_file; };
    category network { network_file; };
    category update { update_file; };
    category dispatch { dispatch_file; };
    category dnssec { dnssec_file; };
    category lame-servers { lame-servers_file; };