title: UITableView section header is all black
body: <p>For an iPhone, I've got a UITableView that is grouped, has one section, and in which I've set up a section header that's a UILabel object from the nib.  When the table view displays, the header shows up as a stripe of solid black -- no text.</p>
  
  <p>In heightForHeaderInSection I've set the height to be the frame.size.height of the UILabel object.  When I change the height in IB, the black stripe's height changes.  So I know that the .m file has latched on to the right UILabel object.</p>
  
  <p>In the debugger, in viewForHeaderInSection, it seems that the width of the UILabel object is zero, and the height is 1079574528, and the text is null.</p>
  
  <p>Any thoughts on what I'm doing wrong?</p>