>>Shooting in the dark: What happens if the WinZip command is not worked directly from Dotnet,
>>but written into a .Bat file, which in turn is called from Dotnet, perhaps after and before REM/Echo commands?
>Haven't had the time to try this one out yet.

Just a try to live with a problem where you don't have the source ;-)
>
>>- Have you tried pruning the file list of files with identical file size,
>
>When removing the duplicate file, same file renamed differently, the problem goes away.
>
>> adding the files, which are non-filesizedistinct to a second, third and so on command line,
>
>Not sure what you mean here.

As the problem goes away if there are no identical files in the que,
another band-aid is to make sure of the above. If the file sizes are distinct for the que,
no problem can happen.
So strategy might be to have a seperate "add" step for possible duplicate files.

>> which will be ***added*** to zip from preivious command line if it exists ?

>I haven't seen that support yet on the WinZip command line utility. Is this something that is possible?

Dunno on WinZip specifics - was supported in old pkarc, pkzip and on the libraries I used afterwards.
Respectfully grinning: RTFM ;-)

>>- had the copied file causing the error in Dotnet identical time info as well
>Not sure what you mean here.

In our network a copy
from X to Share Y started on X will result in the files on Y having current time,
from Share X to Y started on Y will result in the files on Y having same time info as on X.

Might be something specific set up in our network - not my best area.

>> or would a "touch" altering this info allow the Dotnet process to work in 1 shot ?

>Works all the time except when same file is added to the list of files to be zipped under a different name.

Does the error also happen when file itself is identical,
***but the only descriptive time info saved in the directory, not file payload, is different*** ?
In the early days there were "touch" programs setting time info to current time, for compiler chains and so on.

For Zip functionality I also switched over to programmers libraries, but the reasons you cite are familiar,
as we do the same when RAR-ing. So I probed the grey matter for patch/band aid ideas ;-)

regards

thomas