title: PHP Session ID being regenerated automatically
body: <p>I have found that on my simple web application, if you leave the page alone for more than about five minutes and then reload the page, calling session_id() will return a different value the second time. Users remain logged in, so the session data is being moved across to the new ID, but I keep track of cart items in a MySQL database based on the session ID, and when the ID changes, the association with the cart items is lost.</p>
  
  <p>Nowhere in my code do I ever call session_regenerate_id()</p>
  
  <p>Help!</p>