Wildcarded nameservers

[dushy]

Hi,
I run a bind 9.2.1 nameserver with the following configuration.

//named.conf
options {
directory "/var/named";
pid-file "named.pid";
allow-recursion {127.0.0.1 <http://127.0.0.1>;};
};

logging {
category default { default_syslog; default_debug; };
};

zone "." IN {
type master;
file "named.rr";
allow-update {none;};
allow-transfer {none;};
notify no;
};

//named.rr
$TTL 86400
@ IN SOA . hostmaster.mydomain.com <http://hostmaster.mydomain.com>. (
2005090201 ; Serial
28800 ; Refresh
14400 ; Retry
3600000 ; Expire
1 ) ; Minimum
IN NS dns1.mydomain.com <http://dns1.mydomain.com>.
IN NS dns2.mydomain.com <http://dns2.mydomain.com>.
IN A 209.xx.xx.xx
* IN A 209.xx.xx.xx

dns1.mydomain.com <http://dns1.mydomain.com>. IN A 69.xx.xx.xx
dns2.mydomain.com <http://dns2.mydomain.com>. IN A 69.xx.xx.xx

I use this as a wildcarded nameserver i,e for any domain that i wish to 
host, i change the nameservers 
for that domain to dns1.mydomain.com <http://dns1.mydomain.com> and 
dns2.mydomain.com <http://dns2.mydomain.com>.

This works very well, however i have noticed something strange happening in 
the last few days. My webserver, started 
receiving traffic for domains that is not hosted on this webserver. Whois 
shows that there nameservers are different and 
logically my webserver should not be receiving that domains traffic. At the 
same time, i checked up dns lookups for this 
domain name from lot of different sources and they all seem to be pointing 
to the original IP address of that domain and 
not to my webserver.

This makes me believe that some buggy nameservers cached my nameserver as 
"." and are sending requests for any 
domain to my dns server which returns my web server IP address for any 
domain queried. 

A normal dns response from my nameserver is below.

[root at xbox root]# dig @dns1.mydomain.com <http://dns1.mydomain.com>
test.com<http://test.com>

;; QUESTION SECTION:
;test.com. IN A

;; ANSWER SECTION:
test.com <http://test.com>. 86400 IN A 209.xx.xx.xx

;; AUTHORITY SECTION:
. 86400 IN NS dns1.mydomain.com <http://dns1.mydomain.com>.
. 86400 IN NS dns2.mydomain.com <http://dns2.mydomain.com>.

;; ADDITIONAL SECTION:
dns1.mydomain.com <http://dns1.mydomain.com>. 86400 IN A 69.xx.xx.xx
dns2.mydomain.com <http://dns2.mydomain.com>. 86400 IN A 69.xx.xx.xx

Can this cause the problem i have described ? Would changing the TTL to 1 
and setting 
minimal-reponses to yes solve the problem ?

TIA
dushyanth