title: iPhone not displaying background images correctly
body: <p>I've just built a site with four content blocks sitting ontop of one another to create a longish page.</p>
  
  <p>Each block is the full width of the screen and the height of the screen and has a background image.</p>
  
  <p>Now when the site loads it shows the first block and the background image displays correctly. When the user scrolls to the second block the background image does not display until the majority of the block is in the viewport then it will load.</p>
  
  <p>Does anyone know why this would be the case, is it an iOS issue?</p>