this happens because the swf contains a timestamp!
Is it possible to compile a swf without this timestamp, so that the compilation is deterministic? I find this behaviour pretty annoying. We have a big project with hundreds of swfs, and we want to build everything on every release to avoid missing any changes. However swfs whose source is not modified should remain identical so that clients can cache them. It's unfortunate to download hundreds of kilobytes just because a timestamp changed.