netcat port-bynum mismatch error

felipe@cheetah:~> netcat -zvv google.com 80
DNS fwd/rev mismatch: google.com != py-in-f99.google.com
DNS fwd/rev mismatch: google.com != jc-in-f99.google.com
DNS fwd/rev mismatch: google.com != eh-in-f99.google.com
Warning: port-bynum mismatch, 80 != 0
Warning: port-bynum mismatch, 80 != 0
google.com [64.233.167.99] 80 (spr-itunes) open
 sent 0, rcvd 0
felipe@cheetah:~> 

This happens with ANY host I choose (including localhost). I get a “port-bynum mismatch” Warning that my <PORT NUMBER> != 0 What the heck is this all about? And, why does it say “spr-itunes” for all port types, including 80,22,21? I searched Webpin for other netcats, i only found the bsd one. Too lazy to bother installing for such an old (stable?) software that should be working already.

Any ideas what might be going on? I have SmoothWall as my gateway/firewall, if that helps…

Why not use nmap instead, it has more options than the zero I/O scanning mode of netcat?