This is a bug that has been introduced to Zerberus in recent builds. Judging by the behavior, it would appear that only the first half of stereo OGG files are loaded into RAM. Zerberus attempts to play the entire length of the OGG file, but since only the first half is loaded, the second half plays whatever happens to be in memory at that location, which could be data or part of another sample.

This bug does not affect mono OGG files, nor does it seem to affect stereo WAV files. I haven't tested other audio formats.
Steps to reproduce:
1. Copy the attached .sfz and its associated samples folder into MuseScore's "Soundfonts" folder.
2. Load the attached .mscz file.
3. Go to View -> Synthesizer and click "Load from score".
4. Play the score from the beginning.

Result: The second half of the stereo waveform playback will sound like noise or incorrect wave data.