what are you doing with LSZip from your setup.exe? Do you decompress a ZIP archive during the installation process?

But to answer the question, there are no known issues with LSZip. LSZip always checks the original CRC-32 value against the CRC-32 value after the decompression process.

Additional note: the SetupBuilder compiler and installer are using the LSPack (not LSZip). From the technical point-of-view, it is absolutely impossible that LSPack alters the contents of a file. During the compression process (when you build the setup.exe), it generates the CRC-32 value of the file and stores it in the archive header and in the script. After the decompression process, it generates again the CRC-32 value of the decompressed file and checks it against the stored CRC-32 value.