Stick it in a folder with "background01.jpg" and "background.02.jpg." Run it. Test it. Turn it into an app. Put a *different* background01.jpg and background02.jpg in the MacOS directory. Run it again. It will keep the whatever image was displaying in the patch when you turn it into an app even if you put a different one in the MacOS directory. ie. If background01.jpg was displayed in the patch when it is turned into an app, you can't replace background01.jpg. It is cached so to speak.
This has only been a problem for me in max 4.5.