title: Can no longer install WordPress on MAMP- "Fatal error: Cannot redeclare class wpdb"
body: <p>I've been developing WordPress sites for a long time on my local MAMP server.  Now all of a sudden, it won't let me create any new sites.  Whenever I set up a new one, instead of running the install script I get:</p>
  
  <blockquote>
    <p>Fatal error: Cannot redeclare class
    wpdb in
    /Applications/MAMP/htdocs/[my_site]/wp-includes/wp-db.php
    on line 52</p>
  </blockquote>
  
  <p>This happens with all WordPress versions.  I cannot thing of anything that would have caused this.  I've done everything short of re-install MAMP.  Does anyone have any ideas?  I'm desperate at this point..</p>