UIButton's titleLabel.text is not displayed on Cocoa Touch-Collection of common programming errors

After I create a new UIButton at runtime, and set its titleLabel’s text, the button’s text is still not displayed.

What am I doing wrong?

-(IBAction) cloneMe: (id) sender{

    if (!currentY) {
        currentY = [sender frame].origin.y;
    }

    UIButton *clone = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    CGRect cloneFrame = [sender frame];
    cloneFrame.origin.y += currentY + cloneFrame.size.height + 30;
    clone.frame = cloneFrame;
    [clone titleLabel].text = @"I'm a clone";

    [[sender superview] addSubview:clone];

    currentY = cloneFrame.origin.y + cloneFrame.size.height;


}