Replying to a message of JEAN PARROT to BOB ACKLEY:

 JP>     Hello Bob, nice talking to you !  

 BA>> The old version(s) of zip/unzip may not work properly with files
 BA>> zipped with newer version(s).

 JP>         My version of BW and its provided zip-unzip apps are dated    
 JP> 1998 and have not given me an iota of trouble.

The problem may be that your uplink changed to a newer version
that does things differently and your versions don't properly handle
packets zipped with the newer version of the software.  Unfortunately,
many vendors don't consider backward compatibility when bringing out
new software versions.

One reason IBM's mainframe OS's became so huge (don't know about Z-OS)
is that they have to run old software compiled on 1960s versions of the OS
in addition to new software.  On their midrange systems, OS/400 was designed
from the gitgo to be able to run programs written for SSSP (IBM's OS for their
System/3 line of hardware that the AS/400 was to replace) without modification.
IBM was very concerned about backward compatibility, I don't know if they still
are.

--- FleetStreet 1.19+