Is there something wrong with the sound?

1. Open attached score.
2. Play.
3. Listen from bar 3.

Result: The sound starts to change.

Discussion: Trying to ignore the differing positions of the crescendo compared to 1.2, is the different sound just the dynamics changing? Sounds as if it's just the tone, perhaps.

Using MuseScore 2.0 Nightly Build (5491) - Mac 10.7.3.