I've changed the interface provided by Sun, in my assignment it is called DB, to generate correct JavaDocs. I didn't change any method signature or any other sensitive information, just the comments, adding some @param here and @return there. I know we are not suppose to touch this interface, but do you think I did the wrong thing changing its comments to conform to the JavaDocs style?
I think that what you are doing is perfect. We do need to provide JavaDoc for all submitted classes and interfaces, so we have to change the provided comments (IMHO). As long as you don't touch the method signatures you are fine.