UIScrollView and UIButton, UIButtons Disappearing

I have an UIScrollView where I create two UIButtons. The first button works as it should, however the second button disappears. It is still there and can accept clicks, and becomes visible when you click on the hidden button.

Any ideas on why the second button appears?

cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];


button_1        = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain];

button_1.titleLabel.font                          = [UIFont systemFontOfSize:12];;
button_1.titleLabel.lineBreakMode         = UILineBreakModeTailTruncation;
button_1.contentVerticalAlignment         = UIControlContentVerticalAlignmentCenter;
button_1.contentHorizontalAlignment       = UIControlContentHorizontalAlignmentCenter;

[button_1 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[button_1 setTitle:@"Circle" forState:UIControlStateNormal];            
button_1.frame = CGRectMake(0.0, 30.00, 50, 20);    
[button_1 addTarget:self action:@selector(buttonPressed:) forControlEv开发者_JAVA百科ents:UIControlEventTouchUpInside];
[cell.contentView addSubview:button_1];


button_2        = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain];

button_2.titleLabel.font                          = [UIFont systemFontOfSize:12];;
button_2.titleLabel.lineBreakMode         = UILineBreakModeTailTruncation;
button_2.contentVerticalAlignment         = UIControlContentVerticalAlignmentCenter;
button_2.contentHorizontalAlignment       = UIControlContentHorizontalAlignmentCenter;

[button_2 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[button_2 setTitle:@"Square" forState:UIControlStateNormal];            
button_2.frame = CGRectMake(0.0, 120.0, 50, 20);    
[button_2 addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
[cell.contentView addSubview:button_2];

What is the layout you're trying to achieve here? Table cells are, by default (unless you have custom rowHeights) 44px high. Your button_2 is going to be way out of the cell's bounds, far below the first button. Also, there's no reason to, and in fact you should not, retain the buttons you're creating. They'll be retained, when you add them to their parent view.