>>That doesn't sound like 'resolving the issue' - more like 'hiding the symptoms' :-}
>>
>>Was there an overlap between the files being deleted and the files to be compressed?
>>Where were you sending the Winzip error output ?
>
>This is a bug with the WinZip command line utility. Many have reported weird symptoms with that one. Sometimes, it just hangs in the task manager. When this is the case, we have to stop the process.
>
>On a file with 30 MB, I had to increase the timeout to 7 seconds, after the unzip is done, so the next command line could see the files. Otherwise, even if the unzip is done, the application cannot see the files. Or, could it be that this is being executed unattended when we change something in the RedirectStandard options?

If you are executing command line commands, you might want to use a batch with the the START command with the WAIT parameter to make sure commands finish before proceeding.