muse plays strange notes when using internal softsynth

[nexangelus]

I am trying to use the internal softsynths. I have followed the guide here:

http://www.muse-sequencer.org/wiki/index.php/Tutorial1

I can get it working great. Except for one thing. On certain 'D' notes, I get a tone that is an octave plus or minus a half-step above what the tone should be. Then, it echoes twice.

I have tried other soundfont files, and they do the same thing.

I'm using version 0.7.2pre2.

Would anyone have any idea on what is causing that and/or what I could do to fix it?