gif2png in non-free?

[Brian Ristuccia <brianr@osiris.978.org>]

The license for gif2png looks pretty free to me. According to the Free
Software Foundation, programs that decompress gif files are non governed by
the IBM and UNISYS patyents. Are there other issues with gif2png that I'm
overlooking?

http://www.fsf.org/philosophy/gif.html

  gif2png (version 0.6 beta)

  Copyright (C) 1995 Alexander Lehmann

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications (see below), and to alter it and
  redistribute it freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  4. Binary only distributions of the software must include the file README
     with the copyright statement. You are welcome to add a copyright
     statement for your modifications and a contact address, though.

Part of this program (gifread.c) carries the following copyright:

/* +-------------------------------------------------------------------+ */
/* | Copyright 1990 - 1994, David Koblas. (koblas@netcom.com)          | */
/* |   Permission to use, copy, modify, and distribute this software   | */
/* |   and its documentation for any purpose and without fee is hereby | */
/* |   granted, provided that the above copyright notice appear in all | */
/* |   copies and that both that copyright notice and this permission  | */
/* |   notice appear in supporting documentation.  This software is    | */
/* |   provided "as is" without express or implied warranty.           | */
/* +-------------------------------------------------------------------+ */

-- 
Brian Ristuccia
brianr@osiris.978.org
bristucc@nortelnetworks.com
bristucc@cs.uml.edu