Duplicate XML sections keep accumulating

Hello,

I have a score based on the Jazz stylesheet, and for which I changed the main instrument (piano) to a steel drum midi patch. Recently, I noticed that several synthesizer sections keep accumulating in the XML file, every time I update and save the score, and eventhough I don't modify the data in question. The duplicate sections are the following (in fact, it is the whole contents of the synthesizer section). Everytime I save the score, the whole bunch of code below appears once more.

<master>
<val id="0">Zita1</val>
<val id="1">NoEffect</val>
<val id="2">0.1</val>
<val id="3">440</val>
<val id="4">1</val>
<val id="5">1</val>
</master>
<Fluid>
<val id="0">MuseScore_General.sf3</val>
</Fluid>
<Zerberus>
</Zerberus>
<Zita1>
<val id="0">0.25</val>
<val id="1">0.462756</val>
<val id="2">0.161809</val>
<val id="3">0.333333</val>
<val id="4">0.25</val>
<val id="5">0.335245</val>
<val id="6">0.5</val>
<val id="7">0.664755</val>
<val id="8">0.5</val>
<val id="9">0.33</val>
</Zita1>