Program: 104245
Project: 104245
Buggy source:
private void internalPaintComponent(Graphics g){
  AntialiasingManager.activateAntialiasing(g);
  if (isOpaque()) {
    g.setColor(getBackground());
    g.fillRect(0,0,getWidth(),getHeight());
  }
  if (this.bgImage != null) {
    Image paintBgImage;
    if (this.iconImage == null && !isEnabled()) {
      paintBgImage=new ImageIcon(LightGrayFilter.createDisabledImage(bgImage)).getImage();
    }
 else     paintBgImage=bgImage;
    g.drawImage(paintBgImage,this.getWidth() / 2 - this.bgImage.getWidth(null) / 2,this.getHeight() / 2 - this.bgImage.getHeight(null) / 2,this);
  }
  if (this.iconImage != null) {
    Image paintIconImage;
    if (!isEnabled()) {
      paintIconImage=new ImageIcon(LightGrayFilter.createDisabledImage(iconImage)).getImage();
    }
 else     paintIconImage=iconImage;
    g.drawImage(paintIconImage,this.getWidth() / 2 - this.iconImage.getWidth(null) / 2,this.getHeight() / 2 - this.iconImage.getHeight(null) / 2,this);
  }
  FadeTracker fadeTracker=FadeTracker.getInstance();
  float visibility=this.getModel().isRollover() ? 1.0f : 0.0f;
  if (fadeTracker.isTracked(this,FadeKind.ROLLOVER)) {
    visibility=fadeTracker.getFade(this,FadeKind.ROLLOVER);
  }
  g.setColor(new Color(1.0f,1.0f,1.0f,visibility / 2));
  if (this.bgImage != null) {
    g.fillRoundRect(this.getWidth() / 2 - this.bgImage.getWidth(null) / 2,this.getHeight() / 2 - this.bgImage.getHeight(null) / 2,bgImage.getWidth(null),bgImage.getHeight(null),10,10);
  }
 else {
    g.fillRoundRect(0,0,this.getWidth(),this.getHeight(),10,10);
  }
  if (this.getModel().isPressed()) {
    if (this.pressedImage != null) {
      g.drawImage(this.pressedImage,0,0,this);
    }
 else     if (this.iconImage != null) {
      g.drawImage(this.iconImage,this.getWidth() / 2 - this.iconImage.getWidth(null) / 2 + 1,this.getHeight() / 2 - this.iconImage.getHeight(null) / 2 + 1,this);
    }
  }
}

Fixed version (ground truth):
private void internalPaintComponent(Graphics g){
  AntialiasingManager.activateAntialiasing(g);
  if (isOpaque()) {
    g.setColor(getBackground());
    g.fillRect(0,0,getWidth(),getHeight());
  }
  if (this.bgImage != null) {
    Image paintBgImage;
    if (this.iconImage == null && !isEnabled()) {
      paintBgImage=new ImageIcon(LightGrayFilter.createDisabledImage(bgImage)).getImage();
    }
 else     paintBgImage=bgImage;
    g.drawImage(paintBgImage,this.getWidth() / 2 - this.bgImage.getWidth(null) / 2,this.getHeight() / 2 - this.bgImage.getHeight(null) / 2,this);
  }
  if (this.iconImage != null) {
    Image paintIconImage;
    if (!isEnabled()) {
      paintIconImage=new ImageIcon(LightGrayFilter.createDisabledImage(iconImage)).getImage();
    }
 else     paintIconImage=iconImage;
    g.drawImage(paintIconImage,this.getWidth() / 2 - this.iconImage.getWidth(null) / 2,this.getHeight() / 2 - this.iconImage.getHeight(null) / 2,this);
  }
  FadeTracker fadeTracker=FadeTracker.getInstance();
  float visibility=this.getModel().isRollover() ? 1.0f : 0.0f;
  if (fadeTracker.isTracked(this,FadeKind.ROLLOVER)) {
    visibility=fadeTracker.getFade(this,FadeKind.ROLLOVER);
  }
  visibility/=2;
  g.setColor(new Color(1.0f,1.0f,1.0f,visibility));
  if (this.bgImage != null) {
    g.fillRoundRect(this.getWidth() / 2 - this.bgImage.getWidth(null) / 2,this.getHeight() / 2 - this.bgImage.getHeight(null) / 2,bgImage.getWidth(null),bgImage.getHeight(null),10,10);
  }
 else   if (isContentAreaFilled() || (visibility != 0.0f)) {
    g.fillRoundRect(0,0,this.getWidth(),this.getHeight(),10,10);
  }
  if (this.getModel().isPressed()) {
    if (this.pressedImage != null) {
      g.drawImage(this.pressedImage,0,0,this);
    }
 else     if (this.iconImage != null) {
      g.drawImage(this.iconImage,this.getWidth() / 2 - this.iconImage.getWidth(null) / 2 + 1,this.getHeight() / 2 - this.iconImage.getHeight(null) / 2 + 1,this);
    }
  }
}