wont respond to keyboard up left and space, at the same time

[omniscient232]

Hello, I have 2 functions for releasing and pressing keys, for the 5 buttons: arrow buttons and space. there are no problems at all when i dont press space, everything works. but when I press space, and then left and up at the same time, the last 2 wont respond. if i press either of them first, and then the other after that, only the last one of them wont respond. strangely, this doesnt happen when i press left and down, right and down, or up and right. only with left and up.
these are the functions:

protected function keyPressed(e:KeyboardEvent):void
        {
            if (Boolean(keysDown[e.keyCode]))
                {return;}
            keysDown[e.keyCode] = true;
            switch (e.keyCode)
            {
                case (LEFT)://arrow-left
                    kine.setHSpeed(-SPEED);
                    break;
                case (UP)://arrow-up
                    kine.setVSpeed(-SPEED);
                    break;
                case (RIGHT)://arrow-right
                    kine.setHSpeed(SPEED);
                    break;
                case (DOWN)://arrow-down
                    kine.setVSpeed(SPEED);
                    break;
                case (SPACE)://shift
                    weapon.shoot(x,y);
                    shootTimer.start();
                    break;
                default:
                    return;
            }
        } 

and for releasing:

protected function keyReleased(e:KeyboardEvent):void
        {
            keysDown[e.keyCode] = false;
            switch (e.keyCode)
            {
                case (LEFT)://arrow-left
                    //trace("left key released");
                    if (keysDown[RIGHT])
                    {
                        kine.setHSpeed(SPEED);
                    }
                    else
                    {
                        kine.setHSpeed(0);
                    }
                    break;
                case (UP)://arrow-up
                    //trace("up key released");
                    if (keysDown[DOWN])
                    {
                        kine.setVSpeed(SPEED);
                    }
                    else
                    {
                        kine.setVSpeed(0);
                    }
                    break;
                case (RIGHT)://arrow-right
                    //trace("right key released");
                    if (keysDown[LEFT])
                    {
                        kine.setHSpeed(-SPEED);
                    }
                    else
                    {
                        kine.setHSpeed(0);
                    }
                    break;
                case (DOWN)://arrow-down
                    //trace("down key released");
                    if (keysDown[UP])
                    {
                        kine.setVSpeed(-SPEED);
                    }
                    else
                    {
                        kine.setVSpeed(0);
                    }
                    break;
                case (SPACE)://shift
                    shootTimer.reset();
                    break;
            }
        } 

I cant find the problem atall. have been looking for it quite some time.

Thanks, in advance.