title: Slickgrid possible bug: only upper rows are visible
body: <p>I am working with Slickgrid and only upper rows are being visible. These upper rows update when I scroll down, but the others keep hidden/blank.</p>
  
  <p>The problem is <strong>fixed if you change a column position</strong> with your mouse.</p>
  
  <p>I tried removing some columns, disabling different plugins and calling invalidate/render functions with no success.</p>
  
  <p>Why is it happening? Any idea?</p>
  
  <p>Thanks in advance!</p>