title: Excel not discarding original data despite merging cells - causing problems with functions (e.g. sum)
body: <p>When merging cells, Excel normally gives the message: "merging cells only keeps the upper-left values and discards other values". </p>
  
  <p>In some cases this doesn't happen, and the data remains in the cells hidden behind the merged cell. (I am not using align across selection).</p>
  
  <p>Is there a way to prevent this from happening? I have noticed it a few times in a sheet I am working on (<a href="http://www.filedropper.com/160605excelmergedcellsproblem" rel="nofollow">attached example</a> and <a href="http://i.stack.imgur.com/6cRzy.png" rel="nofollow">screenshot</a>).</p>