I'm using MIUI 2.4.13 for the Samsung Galaxy S II. When you open the music app from either of the widgets, it takes you to the now playing screen. However, there is no way to go back to select a new artist/album/song etc. When you press the back button from here, it just closes the app. If you open the app from the icon, it takes you directly to the home screen where you can still see what is playing along with having options to change the music that you are listening to. While this may be more of a refinement than a bug, I believe clicking on the widget should take you to the same screen that the icon takes you to, or at least have a way to get back to this screen.