Java 2D Game - Overcoming Max Of Three Keys At A Time Limitation Of Keyboard

I'm working on a Java 2D game which requires a max of six keys be held down at the same time.

The game is for two players on the same keyboard, playing simultaneously.

However, all three computers I ran the program on only allow a max of three keys held at a time. They all have trouble with reacting to more than three keys being held.

It seems that pressing a new key after three are already held, either cancels some other key-holding or is ignored.

I've been told that this is a hardware issue. Most keyboards can't handle more than three keys held at a time. But a lot of games do require this, and they do not require special gaming-keyboards to run on my computer without problems.

So there has to be a solution that will make the game playable on any standard keyboard.

(I use Key Bindings).

The game's controls:

Player 1

- Rotate sprite and set angle of movement: LEFT arrow

- Rotate sprite and set angle of movement: RIGHT arrow

- Move forward: UP arrow

- Shoot missile: ENTER key

Player 2

- Rotate sprite and set angle of movement: 'A' key

- Rotate sprite and set angle of movement: 'D' key

- Move forward: 'W' key

- Shoot missile: 'T' key

Relevant code:

The Key Bindings part:

Java Code:

// An action for every key-press.
// Each action sets a flag indicating the key is pressed.
leftAction = new AbstractAction(){
public void actionPerformed(ActionEvent e){
keysPressed1[0] = true;

[Code] .....

This is mostly how reacting to key-presses and key-releases works in my program. When a key is pressed or released, a flag is set. The Board class reades the flags every game-loop cycle and reacts accordingly.

As I said, the program doesn't react correctly to more than 3 keys held at a time, probably because of the keyboard. Is there a way to code a solution?