Known, current PKZIP bugs/limitations:
-------------------------------------

 - PKUNZIP 2.04g considers volume labels valid only if originated on a FAT
   file system, but other OSes and file systems (e.g., Amiga and OS/2 HPFS) 
   support volume labels, too

 - PKUNZIP 2.04g can restore volume labels created by Zip 2.x but not by
   PKZIP 2.04g (OS/2 DOS box only??)

 - PKUNZIP 2.04g gives an error message for stored directory entries created
   under other OSes (although it creates the directory anyway), and PKZIP -vt
   does not report the directory attribute bit as being set, even if it is

 - PKZIP 2.04g mangles unknown extra fields (especially OS/2 extended attri-
   butes) when adding new files to an existing zipfile [example:  Walnut Creek
   Hobbes March 1995 CD-ROM, FILE_ID.DIZ additions]

 - PKUNZIP 2.04g is unable to detect or deal with prepended junk in a zipfile,
   reporting CRC errors in valid compressed data.

 - PKUNZIP 2.04g (registered version) incorrectly updates/freshens the AV extra
   field in authenticated archives.  The resultant extra block length and total
   extra field length are inconsistent.

 - [Windows version 2.01] Win95 long filenames (VFAT) are stored OK, but the
   file system is always listed as ordinary DOS FAT.

 - [Windows version 2.50] NT long filenames (NTFS) are stored OK, but the
   file system is always listed as ordinary DOS FAT.

 - PKZIP 2.04 for DOS encrypts using the OEM code page for 8-bit passwords,
   while PKZIP 2.50 for Windows uses Latin-1 (ISO 8859-1).  This means an
   archive encrypted with an 8-bit password with one of the two PKZIP versions
   cannot be decrypted with the other version.

 - PKUNZIP 2.04g is reported to have problems with archives created on and/or
   copied from Iomega ZIP drives (irony, eh?).

Known, current WinZip bugs/limitations:
--------------------------------------

 - [16-bit version 6.1a] NT short filenames (FAT) are stored OK, but the
   file system is always listed as NTFS.

 - WinZip doesn't allow 8-bit passwords, which means it cannot decrypt an
   archive created with an 8-bit password (by PKZIP or Info-ZIP's Zip).

Possibly current PKZIP bugs:
---------------------------

 - PKZIP (2.04g?) can silently ignore read errors on network drives, storing
   the correct CRC and compressed length but an incorrect and inconsistent
   uncompressed length.

 - PKZIP (2.04g?), when deleting files from within a zipfile on a Novell
   drive, sometimes only zeros out the data while failing to shrink the
   zipfile.

Other limitations:
-----------------

 - PKZIP 1.x and 2.x encryption has been cracked (known-plaintext approach;
   see http://www.cryptography.com/ for details).

[many other bugs in PKZIP 1.0, 1.1, 1.93a, 2.04c and 2.04e]