When I use touchesBegan on my sprite kit game the buttons press down fine the first time but are unresponsive the second time, how do I "reset" these buttons if you will. Buttons are as follows:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint location = [touch locationInNode:self];
    SKNode *node = [self nodeAtPoint:location];


    if ([node.name isEqualToString:@"Button"]) {

        [self runAction:[SKAction playSoundFileNamed:@"sound" waitForCompletion: NO]];
        ....

Thanks for your help!