Dlink LB604 bug?

Hi guys!

I have setup a CENTOS 5 dns server.
Everything is working fine, even the load balance feature.
Now the problem starts when I login to remote linux server and type
the command:

[root@rm ~]# nslookup mydomain.com 196.46.2.67
;; reply from unexpected source: 196.28.239.xx#53, expected
196.46.2.xx#53
;; reply from unexpected source: 196.28.239.xx#53, expected
196.46.2.xx#53
;; connection timed out; no servers could be reached

[root@rm ~]# nslookup mydomain.com 196.28.239.60
Server: 196.28.239.xx
Address: 196.28.239.xx#53

Name: mydomain.com
Address: 196.28.239.xx
Name: mydomain.com
Address: 196.46.2.xx

Sometimes the answer comes from my WAN1 and sometimes answer comes
from WAN2.
This is not good, I want to get the answer from the ip I requested.

Any help please?

Check the named.conf configuration below:
recursive-clients 100;
//interface-interval 0;
minimal-responses yes;
//notify no;
recursion yes;
version "";
transfer-format many-answers;
allow-recursion {192.168.1.0/24; 127.0.0.1;};
//allow-notify { localhost; };
allow-transfer { localhost; };
forwarders { 196.28.xx.xx; 196.46.0.xx;};
listen-on port 53 {any;};
query-source address * port 53;
notify-source * port 53;
transfer-source * port 53;
auth-nxdomain no;
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";

The router is a Dlink LB604. Load balance is enabled, but I don´t
think that´s the problem since i have tested with load balance
disabled.

Help!