UITapRecognizer and ImageView

I have a UIImageView with a UITapGestureRecognizer attached. This is just a ball moving around the scree开发者_运维问答n. It moves once a second.

ball.image = [UIImage imageNamed:@"chicken.png"];
ball.frame = CGRectMake(160, 160, 50, 50);
ball.autoresizesSubviews = NO;
speed = 10;
objTimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(ballMove:) userInfo:nil repeats:YES];
recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];

The method called when the imageView is clicked is

-(void)handleTap:(UITapGestureRecognizer *)sender
{
    CGPoint obj = [sender locationInView:ball];
    NSLog(@"x = %f",obj.x);
    NSLog(@"y = %f",obj.y);
    .......
}

It doesn't grab all taps. It only picks up taps where y is less than 1 however.

x = 14.958618
 y = 0.879913
x = 23.996643
 y = 0.975830
 x = 24.542923
y = 0.557907

And so on...

The imageView description is: <UIImageView: 0x6814800; frame = (161.747 183.826; 50 1); opaque = NO; autoresize = W+H; autoresizesSubviews = NO; layer = <CALayer: 0x6814880>>

Check whether your UIImageView interactions are enabled:

ball.userInteractionEnabled = YES;