I finally found why I had a stack overflow error.
Since I have two controllers (one for the application and one for the individual dots), and both of them call a mouseListener method from their related view, there was confusion between the names. I had named both calling methods addMouseListener().
I gave them different names and now the error is gone. (Few, it took me three days to think of that.)
So, I'll close this thread in a few days. If someone would like to add a comment, please do. Especially if it would help me improve my program.
I have a few more questions to ask concerning MVC, but I'll create a new thread for those.
Thanks again for your suggestion, Chris.