Lame Server

[Bill.Light at kp.org]

I have DNS working - or so I thought.   Now I have set up e-mail using my 
own postfix MTA in a DMZ, I get the "Lame Server" error message on the IP 
address of the firewall - which I would just as soon leave transparent. 
Is that possible, or do I have to "name" the firewall ?

The error

Aug 29 16:40:47 xxxxx named[13215]: lame server resolving 
'122.120.xx.xx.xx.in-addr.arpa' (in '120.xx.xx.xx.in-addr.arpa'?): 
168.143.168.1#53

Other Info:
* It's a SuSE 9.2 box running BIND  9.2.4-3
* SBC has given me a /29 block and I thought it was correct...
* Internal machines are on a 192 subnet and a proxy-arp'd firewall (.122)
  directs the traffic to the DMZ .123 address. 

Where do I look - or is it safe to post the entire "real" 
configuration...just being paranoid.