title: Buttons added to a UIImageView are unresponsive
body: <p>I am using a UIImageView with two buttons added as a subview in my app. However, if I try to click the buttons, they are unresponsive. Is there a reason for this, or a fix?</p>
  
  <pre><code>- (void)showPopover {
      if (isClicked == NO) {
          if (popover == nil) {
              popover = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Popover.png"]];
              [popover setFrame:CGRectMake(190, -10, 132, 75)];
              UIButton *btn1 = [UIButton buttonWithType:UIButtonTypeCustom];
              [btn1 setFrame:CGRectMake(30, 30, 24, 24)];
              [btn1 setBackgroundColor:[UIColor clearColor]];
              [btn1 setImage:[UIImage imageNamed:@"Bookmark.png"] forState:UIControlStateNormal];
              [btn1 addTarget:self action:@selector(addFav) forControlEvents:UIControlStateNormal];
              [popover addSubview:btn1];
  
              UIButton *btn2 = [UIButton buttonWithType:UIButtonTypeCustom];
              [btn2 setFrame:CGRectMake(80, 30, 24, 24)];
              [btn2 setBackgroundColor:[UIColor clearColor]];
              [btn2 setImage:[UIImage imageNamed:@"ButtonBarReload.png"] forState:UIControlStateNormal];
              [btn2 addTarget:self action:@selector(doHud) forControlEvents:UIControlStateNormal];
              [popover addSubview:btn2];
              isClicked = YES;
          }
          popover.alpha = 0.0;
          isClicked = YES;
          [self.view.superview addSubview:popover];
          [UIView beginAnimations:nil context:NULL];
          [UIView setAnimationDuration:1.0];
          popover.alpha = 1.0;
          [UIView commitAnimations];
      }
      else if (isClicked == YES) {
          [popover setAlpha:1.0];
           isClicked = NO;
          [UIView beginAnimations:nil context:NULL];
          [UIView setAnimationDuration:1.0];
          [popover setAlpha:0.0];
          [popover removeFromSuperview];
          [UIView commitAnimations];
          popover = nil;
          [popover release];
      }
  }
  </code></pre>