Access violation with TSLCRealMatrixBuffer

Code:
int noAdFrames = 0;

int noMovFrames = 0;

bool* frameRead = new bool[responses->GetRows()];

TSLCRealMatrixBuffer* newTrainingData = 0;

TSLCRealMatrixBuffer* newResponses = 0;

int rows = 0;



// initialise to false

for (int i = 0; i < responses->GetRows(); i++) {

    frameRead[i] = false;

}



// count frames

for (int i = 0 ; i < framesStored; i++) {

    if((*responses)[i][0] == MOVIE) {

        noMovFrames++;

    }

    else if ((*responses)[i][0] == AD) {

        noAdFrames++;

    }

}



// determine which type of frame occurs less often and create the

// new training data matrix for double the size of the less often

// frame type

if ( noAdFrames != noMovFrames) {

    if (noAdFrames < noMovFrames) {

        newTrainingData = new TSLCRealMatrixBuffer(noAdFrames * 2, trainingData->GetCols());

        newResponses = new TSLCRealMatrixBuffer(noAdFrames * 2, 1);

        rows = noAdFrames * 2;



    }

    else {

        newTrainingData = new TSLCRealMatrixBuffer(noMovFrames * 2 + 1, trainingData->GetCols());

        newResponses = new TSLCRealMatrixBuffer(noMovFrames * 2 + 1, 1);

        rows = noMovFrames * 2;

    }



    // seed random number generator

    srand( (unsigned)time( NULL ) );



    // fill the new training data matrix with the data from the old matrix



    int loopStop = rows * 0.75;

    for (int i = 0; i < loopStop; i++) {    // only till 75% of the buffer to ensure good performance

        int randomFrame = rand() % framesStored;



        // has this frame already been copied?

        // MOVIE and AD parts should alternate

        while (frameRead[randomFrame] == false

            && ((i % 2 == 0 && (*responses)[i][0] == MOVIE)

            || (i % 2 == 1 && (*responses)[i][0] == AD))) {

            randomFrame = rand() % framesStored;

        }



        // copy data

        newResponses->SetItem(i, 0,

            responses->GetItem(randomFrame, 0));



        for (int j = 0; j < trainingData->GetCols(); j++) {

            newTrainingData->SetItem(i, j,

                trainingData->GetItem(randomFrame, j));

        }



        frameRead[randomFrame] = true;

    }



    // do the remeining 25%

    for (int i = newTrainingData->GetRows() * 0.75; i < framesStored; i++) {

        for (int j = 0; j < trainingData->GetRows(); j++) {

            if (frameRead[j] == false

                && ((i % 2 == 0 && (*responses)[j][0] == MOVIE)

                || (i % 2 == 1 && (*responses)[j][0] == AD))) {

                // copy data

                (*newResponses)[i][0] = (*responses)[j][0];



                for (int v = 0; v < trainingData->GetCols(); v++) {

                    (*newTrainingData)[i][v] = (*trainingData)[j][v];

                }



                frameRead[j] = true;

                break;

            }

        }

    }



    // clean up old pointers

    delete frameRead;

    delete trainingData;

    delete responses;



    // redirect old pointers to new data

    responses = newResponses;

    trainingData = newTrainingData;

}