so i was 100 samples too far, but at 1070 i see no clicks either (D400.png). downloaded the sample anew (named it D400a.png), unzipped with 7zip; no clicks for me, as far as i can hear and see.
have you tried the D400.sf2?
watch the attached .png's
The difference between the two: I viewed this sample with Polyphone software, you viewed it with another wave editor.
Now I looked again with Audacity and you are right, there is no clipping but there is a high dB value (at 0dB).
When I normalize it to -1dB and import it into Polyphone, there is no clip.
In this case, can we say that when the sample goes above a certain dB value, the dll used by Polyphone to load it clips it?