bind in NAT

Hi all,
I'm wondering if anyone has similar problem or know of the issue i'm
having with bind. I couldn't find any info on this on google. The
problem is i couldn't setup bind to be the nameserver for a domain that
has different external IP than my own.

here is my home setup [typical DSL/modem line]:
external if (1.1.1.1) <--> router <-NAT-> internal if on a box run
bind(2.2.2.2)

dig/nslookup work fine for internal view.

With dig and nslookup using the external ip as nameserver quering a
domain that bind is serving always returns the external ip address even
the forward record.
adomainimhosting.com has ip of 3.3.3.3.

Using tcpdump to capture the data return, i see the correct ip in the
message, however, nslookup/dig still shows the external ip but the TTL
is always 0.

Here is the output:

% dig @1.1.1.1 adomainimhosting.com
; <<>> DiG 9.2.5 <<>> @1.1.1.1 adomainimhosting.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12399
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

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

;; ANSWER SECTION:
adomainimhosting.com. 0 IN A 1.1.1.1

;; AUTHORITY SECTION:
myowndomain.com. 86400 IN NS
ns.myowndomain.com.

;; Query time: 84 msec
;; SERVER: 1.1.1.1#53(1.1.1.1)
;; WHEN: Thu Sep 15 17:01:35 2005
;; MSG SIZE rcvd: 63


Thank you for taking time reading this. Please let me know if i'm
doing something wrong.