glutSolidSphere won't work after updating IDE

Hi everyone,
I recently updated to Qt5.1.1 from Qt5.0.2. Since I did this, my formerly fine working code mysteriously doesn’t do what it’s supposed to anymore.
Basically I’m displaying glutSolidSpheres in coordinates read from a file.
Everything works, except for the “seeing a sphere” part. Again, that used to work fine.
My (stripped down) code is

initializeGL()

void GLWidget::initializeGL() {
    glShadeModel(GL_SMOOTH);
    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glEnable(GL_DEPTH_TEST);*/
    glClearColor(0.2,0.2,0.2,1);
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_LIGHT0);
    glEnable(GL_LIGHTING);
    glEnable(GL_COLOR_MATERIAL);
}

resizeGL()

void GLWidget::resizeGL(int width, int height) {
    glViewport(0,0,width,height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(120.0, (float)width/height,0.01,100.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

paintGL()

void GLWidget::paintGL() {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    glTranslatef(0.0f, 0.0f, 0.0f);
    for(iii=0;iii<N_glw-1;iii++) {
        drawsphere(fX_glw[iii], fY_glw[iii], fZ_glw[iii], 'r' /*, true*/);
    }
}

drawsphere() is basically a glorified glutSolidSphere command


        glColor3f(1.0f, 0.2f, 0.2f);
        glPushMatrix();
        glTranslatef(fX, fY, fZ);
        glutSolidSphere(0.5,16,16);
        glPopMatrix();
        glFlush();

Could anyone tell me if I have maybe a perspective problem? I have absolutely no idea why it wouldn’t work just because I updated the IDE.
Thanks a lot!