[report from a user]
Under Windows 7, a user was getting mysterious error messages and crashes during the Zip operation while building a screensaver. The error messages indicated that immediately after a successful build of the screensaver installer, when iScreensaver Designer tried to zip up all the files, some of the files were missing.
An investigation revealed that the user was storing the project files and building the installers within folders managed by Adobe Version Cue (a file synchronizing tool).
We suspect that Version Cue is moving or deleting files during the build process and this is what is causing the issue.
Moving the project files to the Desktop and re-building solved the issue.