JSlider works but doesn't "slide"

I'm currently learning how swing works and trying to write a program that allows a user to add stars to a canvas (an exercise set forth in Roberts' Art and Science of Java). Everything works except the slider, which doesn't actually "slide" when I run it from eclipse. It does what it's supposed to do, (resize the stars), but the slider button itself doesn't move when you grab it and slide left or right. Is this a problem with the code or something strange in Eclipse, perhaps? Any help is appreciated.

import acm.program.*;
import acm.graphics.*;
import java.awt.Color;
import java.awt.event.*;
import javax.swing.*;

/**
 * This program creates a five-pointed star every time the user clicks the mouse on the canvas.  (From Art and Science of Java p. 352)
 * @author Joshua
 *
 */

public class DrawStarMap extends GraphicsProgram {
	
	//Initializes the graphical user interface
	public void init(){
		setBackground (Color.gray);
		add(new JButton ("Clear"), SOUTH);
		sizeSlider = new JSlider(MIN_SIZE, MAX_SIZE, INITIAL_SIZE);
		add (new JLabel ("  Small"), SOUTH);
		add (sizeSlider, SOUTH);
		add (new JLabel("Large  "), SOUTH);
		initColorChooser();
		add (colorChooser, SOUTH);
		addMouseListeners();
		addActionListeners();
	}
		
		//Initializes the color chooser
		private void initColorChooser (){
			colorChooser = new JComboBox();
			colorChooser.addItem("White");
			colorChooser.addItem("Red");
			colorChooser.addItem("Yellow");
			colorChooser.addItem("Orange");
			colorChooser.addItem("Green");
			colorChooser.addItem("Blue");
			colorChooser.addItem("Black");
			colorChooser.setEditable(false);
			colorChooser.setSelectedItem("White");
		}
	
		//Returns the current color
		private Color getCurrentColor (){
			String name = (String) colorChooser.getSelectedItem();
			if (name.equals("Red")) return Color.red;
			if (name.equals("Yellow")) return Color.yellow;
			if (name.equals("Orange")) return Color.orange;
			if (name.equals("Green"))  return Color.green;
			if (name.equals("Blue"))  return Color.blue;
			if (name.equals("Black"))  return Color.black;
			return Color.white;
		}

//Returns the current size
		private double getCurrentSize(){
			return sizeSlider.getValue();
		}
	
	//Called whenever the user clicks the mouse
	public void mouseClicked (MouseEvent e) {
		
		GStar star = new GStar (getCurrentSize());
		star.setFilled(true);
		star.setColor(getCurrentColor());
		add (star, e.getX(), e.getY());
	
	}
	
		
	public void actionPerformed (ActionEvent e) {
		if (e.getActionCommand().equals("Clear")){
			removeAll();
		}
	}

//private constants
	private static final int MIN_SIZE = 1;
	private static final int MAX_SIZE = 50;
	private static final int INITIAL_SIZE = 16;
	
	//private instance variables

private JSlider sizeSlider;
	private JComboBox colorChooser;
}

Furthermore, when you use the JComboBox, it will select the right color, but only shows the default "White" in the combo box.

both the comboBox and slider worked OK for me.

problem is likely to be in your custom classes

Thanks. I'm using Eclipse 4.1; do you have any idea what I might try to change? I think everything is default, since I don't really know enough to mess around with the settings (often I change the application size, but that's all).

doubtful the problem is in eclipse. more likely to be in
extends GraphicsProgram or
addMouseListeners();

perhaps addMouseListeners() removes/overrides the slider/sliderUI listeners

Moving to where we usually discuss GIU questions.