Cocos2D 2.x - Multi-touch is laggy, but no FPS drop

Question

In my new game, I have to handle multi touch with cocos2d to move two players at the same time. However, sometimes it looks like the touches are being laggy! When I play, everything is really smooth but then I get a lag out of nowhere with the players' movement, but the other objects move smoothly! So I decided to run profiling, and everything was fine, my game was always running between 56-60 fps, even with the "lag". So I guess it's not a memory, nor FPS issue, but more a touch handling problem... Here is my code :

- (void) ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches) {
        tapCount ++;

        CGPoint location = [touch locationInView:[touch view]];
        location = [[CCDirector sharedDirector] convertToGL:location];

        //Do my stuff here...

        NSLog(@"Tap Count:%d", tapCount);
    }
}

- (void) ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    if (tapCount == 0) return;

    for (UITouch *touch in touches) {
        CGPoint location = [touch locationInView:[touch view]];
        location = [[CCDirector sharedDirector] convertToGL:location];
        CGPoint prevLocation = [[CCDirector sharedDirector] convertToGL:[touch previousLocationInView:[touch view]]];

        float diff = (location.y - prevLocation.y) / ipadScale * SENSIVITY;

        //MOVE MY PLAYERS HERE
    }
}

- (void) ccTouchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{
    [self ccTouchesEnded:touches withEvent:event];
}

- (void) ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches) {
        tapCount--;
        NSLog(@"Tap Count:%d", tapCount);
    }

    if (tapCount <= 0) {
        tapCount = 0;
        [self pauseGame];
    }
}

I'm also registering my game scene as a Standard Delegate, is it the problem? I guess not because it is required for multi touch! I believe that there ain't nothing wrong with this code neither, am I right? And when I say laggy, it's like running at 25 FPS, that's not a big deal, but kind of annoying!

Please help me! Thank you!