Just noticed that as of Mountain Lion Version 10.8.4, when the screen saver comes on, the existing application or program that has the focus, becomes unfocused. Rather, when unlocking the screensaver, Finder has the focus.
Keeping a focused application is important. If I am recording music, and for a duration of time, the screensaver comes on. Then I want to hit the shift key to wake up the screen, and then press SPACE to stop my recording. However, this simple function use to work, and now does not.. Finder has the focus and not my music program.
For a music station running on a Mac platform, focus needs to remain on the user focused application. Other system routines should not undo user settings.