title: AutoCompleteComboBox Arrow Up/Arrow Down keys to scroll list
body: <p>I created a simple <code>AutoCompleteBox</code> in my <code>WPF</code> app and it loads great with code intercepting the Populate event, but when the list pops up and I hit the arrow down key and get to the end of the list the vertical scroll bar doesn't scroll.  </p>
  
  <p>The values keep changing in the field like it is scrolling through them, but the scroll bar doesn't move.  </p>
  
  <p>If I use the mouse it scrolls fine.  </p>
  
  <p>I just need the arrow key to scroll it.</p>
  
  <p>Any ideas/suggestions?</p>
  
  <p>I am new to <code>WPF</code> and have searched forever for this fix.</p>