I suppose I could have been more clear! :)
I deliberately deleted a file from the directory after the initial processing of the directory but before it could be archived so I could see the error message. I have error messages and stack trace going to a log file in the root of C. An example:
6/19/2009 4:07:44 PM
Could not find file 'C:\Users\jeffy.SELLETHICS\Documents\A_Demo.pst'.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at Ionic.Zip.ZipEntry.FigureCompressionMethodForWriting(Int32 cycle)
at Ionic.Zip.ZipEntry.WriteHeader(Stream s, Int32 cycle)
at Ionic.Zip.ZipEntry.Write(Stream s)
at Ionic.Zip.ZipFile.Save(String zipFileName)
at SMG_Backup.MainForm.ZipSave(String SourceFolder, String DestFile)
As you can see, it tells me which file it had issue with. This is significant to me as it helps troubleshoot more specifically if there is an issue.