No sound with replace pitches

Here is the score, it is just a sketch for testing this feature.
I am starting at measure 19. I am just using the mouse with left clicks.
First, I click on the first note in measure 19, a 32nd note at middle C. I hear the sound of the note when I click it.
Then, click Note Input (N), then click Replace pitches button.
Then I click on notes on the embedded Keyboard in MuseScore 2.0.2. Everything works correctly, each pitch is correctly replaced and the cursor advances from note to note, preserving the original time intervals, but there is no sound.

The behavior is the same if I use the external MIDI keyboard.

Now I notice that if I follow the same steps, but enter notes using the mouse pointer and clicking the notes on the staff, then I get the sounds, but it does not change the existing pitches, instead it is adding pitches to make chords. It adds one pitch (note) to each existing one, then advances to the next note. Isn't that interesting? Of course, I need to use the keyboard.

In summary, with keyboard note clicks, the behavior is correct but there is no sound.
With the mouse note clicks on the staff, the behavior is incorrect, but I am getting the sound.

Thank you very much for your kind help. By the way, I am using Windows XP. I am very new with MuseScore and just got a MIDI keyboard and this seems to be the last issue for me to resolve before I can really get composing.