SoundTouch library messes up the ending when pitch-shifting

Question

I'm using the SoundTouch library to pitch-shift some audio files. Everything works well, except the last few hundred milliseconds of the new audio file are not like the original file. Here is the original file:

And here's what I get after pitch-shifting:

As you can see the ending is not right. It's like there was nothing there in the original file, when there certainly is.

Here's the code I'm using:

int generateFile(WavInFile *file, SoundTouch *st, string fileName, int semitones)
{
  const bool speech = true; 

SAMPLETYPE samples[BUFF_SIZE];

WavOutFile *out = new WavOutFile(fileName.c_str(), (int)file->getSampleRate(), (int)file->getNumBits(), (int)file->getNumChannels());

int nChannels = (int)file->getNumChannels();

assert(nChannels > 0);

int num, nSamples;
int buffSizeSamples = BUFF_SIZE / nChannels;

st->setSampleRate((int)file->getSampleRate());
st->setChannels(nChannels);
st->setPitchSemiTones(semitones);

if (!speech)
{
    st->setSetting(SETTING_USE_QUICKSEEK, 0);
    st->setSetting(SETTING_USE_AA_FILTER, 0);
}
else
{
    st->setSetting(SETTING_USE_QUICKSEEK, 0);
    st->setSetting(SETTING_SEQUENCE_MS, 40);
    st->setSetting(SETTING_SEEKWINDOW_MS, 15);
    st->setSetting(SETTING_OVERLAP_MS, 8);
}



while (file->eof() == 0)
{
    num = file->read(samples, BUFF_SIZE);

    nSamples = num / (int)file->getNumChannels();

    st->putSamples(samples, nSamples);

    do 
    {
        nSamples = st->receiveSamples(samples, buffSizeSamples);
        out->write(samples, nSamples * nChannels);
    } while (nSamples != 0);
}


st->flush();

do 
{
    nSamples = st->receiveSamples(samples, buffSizeSamples);
    out->write(samples, nSamples * nChannels);
} while (nSamples != 0);

delete out;

return 0;

}

And yes, I delete WavInFile *file later in my code. So my question is- Why is SoundTouch doing this and how can I fix it?

Also I cannot simply cut the wrong part of the new audio file because I'm generating hundreds of files this way so cutting every single one of them would be...