Anton Baskanov (@baskanov) commented about dlls/dmsynth/synth.c:
} set_default_voice_connections(fluid_voice);
if (region->wave_sample.cSampleLoops)
{
WLOOP *loop = region->wave_loops;
fluid_voice_gen_set(fluid_voice, GEN_SAMPLEMODE, 3);
Shouldn't the mode depend on loop->ulType?