title: rbind error: "names do not match previous names"
body: <p>As part of a larger problem (adding a <code>,makeUniqueIDs</code> argument to <code>rbind.SpatialPolygonsDataFrame</code> for situations when the polygon IDs are identical), I'm running into this weird message from rbind:</p>
  
  <pre><code>&gt; do.call("rbind",xd.small)
  Error in match.names(clabs, names(xi)) : 
    names do not match previous names
  </code></pre>
  
  <ul>
  <li><a href="https://gist.github.com/3387091" rel="noreferrer">xd.small <code>dput</code> output</a></li>
  </ul>
  
  <p>The only other info I could find on this was <a href="https://stackoverflow.com/questions/2504543/merge-multiple-data-frames-error-in-match-namesclabs-namesxi-names-do-n">this question</a>, which leads me to believe that <code>rbind</code> was at the root of the problem there also.</p>
  
  <p>I can just write my own rbind-like function of course, but presumably this <code>match.names</code> check occurs for a reason, and I'm curious what it is.</p>