Is this a bug of gzip?

[Yiorgos Adamopoulos]

Hi!  I tried to gunzip 
http://www.vitanuova.com/dist/4e/20060303/inferno.tgz using version 
1.3.5 (I work on an Ubuntu 6.06 LTS) and got:

address@hidden:~/tmp$ gunzip inferno.tgz

gunzip: inferno.tgz: invalid compressed data--format violated
address@hidden:~/tmp$ gzip --version
gzip 1.3.5
(2002-09-30)
Copyright 2002 Free Software Foundation
Copyright 1992-1993 Jean-loup Gailly
This program comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of this program
under the terms of the GNU General Public License.
For more information about these matters, see the file named COPYING.
Compilation options:
DIRENT UTIME STDC_HEADERS HAVE_UNISTD_H HAVE_MEMORY_H HAVE_STRING_H 
HAVE_LSTAT ASMV
Written by Jean-loup Gailly.

I get the same error message if I use version 1.3.9.

However, if I use gzip-1.2.4, then everything is OK.

So I am wondering:  Whose bug is this?  Vitanuova's?  Ubuntu's?  gzip's?

Thank you in advance,

./Yiorgos