[squid-users] Unsafe PASV reply

I got this on my log file:

[squid] Unsafe PASV reply from "IP ADDRESS": Entering Passive Mode (192,168,1,1,9,177).

What does it mean?

Slackware 9.0 Beta
------------------------------
pub 1024D/04BAE461 2002-10-22 -JhAzEr- <catsedp@cats.com.ph>
sub 1024g/63BA0ABD 2002-10-22 Mobile Phone: 0920-2625725

Window Manager ---> Ratpoison-1.1.1
Email Client ---> Pygmy-0.6.0
Web Browser ---> Phoenix-0.3 (Lucia)

[gcc-3.2] [gnupg-1.2.0] [gpgme-0.3.9]
Received on Thu Nov 28 2002 - 02:10:27 MST