title: ListBox doesn't scroll properly
body: <p>I am building a Windows Phone 7 app with Silverlight and am having a problem with some ListBoxes.  They only scroll slightly and then return to original position when I attempt to scroll to bottom of list.  Some ListBoxes work fine.  Others do not.  Those that don't work are generally more complex.  </p>
  
  <p>For example, one scenario is I want a ListBox of search results and a button at the bottom of the list to get more results.  The more button should only be visible by scrolling to the bottom of the ListBox.</p>