This might be a silly question, but where and how are the SC modules loaded?

I just did a upgrade form 3.0 to 3.1 by copying the new server JAR files and the new [gwtmodule]\sc and [gwtmodule]\tools folder.
But the users are not able to connect any more to the application unless they first clear their browser cache.

How do I force the browser to reload the JS from gwtmodule\sc\modules ?

My landing page only has script to set isomorphicDir and load the skin and datasource.