Delay Using Key Bindings

I got Key Bindings for a game I'm working on. They're supposed to move objects when keys are pressed.

(currently, each println(..) represents actual code to move things on the screen, will be added later).

The printing in the console works, but with delays. The words "left", "right", etc. appear with a delay in the console, sometimes half a second delay, sometimes a few seconds delay.

There is no delay at all sometimes, but when a lot of keys are pressed one after the other, there's a delay of several seconds, and only then the words suddenly appear in the console (like the computer had too much to handle at the same time).

When I did the same Key Bindings in a different project without all the game logic, only pressing buttons that print words in the console - it worked perfectly without delay.

So I suspect the problem is something with the game code, or the way I used Key Bindings inside the game code.

I tried putting the Key Bindings code in the thread that contains the game-loop (before the game-loop), and in the constructor. Same problem.

Here is the relevant code of the Board class (extending JPanel), the main JPanel of the game which displays the graphics and manipulates objects.

Java Code:

import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Board extends JPanel implements Runnable {
Tank tank1,tank2;
boolean[] keysPressed1,keysPressed2;

[Code] ....

As I said, I suspect the program demands too much of the computer, so pressing a lot of keys one after the other, freezes the program for several seconds, and then suddenly prints the words on the console.