Double-clicking may have been a terrible Windows design idea. It does a lot of different things depending on the context. Many people have just learned over time that you should just double-click everything just to make sure. This makes web application development a bit harder, as you need to anticipate the possibility that people might hit that button twice quickly and so on. Double-clicking on tabs in the Office ribbon will hide the tab and you’ll wonder what happened.
In summary, don’t double-click anything except files you want to open in Windows. Click on links in the web browser once. You can tell the difference between things you want to open and links by…oh, I see the problem. 🙂