1. create a JNLP application, and assoicate it with a specific file-ext/mime-type
2. launch the application, accept association creation
3. now tries to click on the file type that is associated with this app, javawebstart launches the app to handle the file
4. now update the application on the webserver
5. now click on the file type that is assoicated with this application again. this will trigger webstart to launch the application on the client again. javawebstart donwloads the udpate and then uses the application to open the file.
6. now click on the file-ext again. it's not handled by the webstart application anymore!