title: Solr full-import having Problems
body: <p>I am running Sol 3.6 version with 5 cores.I do full import whenever my application starts up.
  I am simply calling http://:/solr//dataimport?command=full-import</p>
  
  <p>As of now i am facing 2 weird issues.</p>
  
  <ol>
  <li>One of the core's data is empty(index got deleted).Dont know why.</li>
  <li>In my query i had put restriction to load only 6 months old data.Sometimes i get data which is much older than 6 months.</li>
  </ol>
  
  <p>Questions :
  What does default "clean=true" mean?In my case it is true.Does that mean i will not see data once i execute following query?
  http://:/solr//select/?q=<em>%3A</em>&amp;version=2.2&amp;start=0&amp;rows=10&amp;indent=on</p>