title: WP Admin extremely slow
body: <p>The WP back end of a site I'm working on (It's a multisite) takes about 25 seconds to load.</p>
  
  <p>Everything was working fine until yesterday and the front end still works perfectly well. All other sites on the same server run just as well, so it MUST be a WP back end issue.</p>
  
  <p>I don't remember exactly what change it was that made it so slow. I remember updating WP recently (to version 3.4.2), adding some plugins on one of the sites and changing the max upload file size.</p>
  
  <p>I tried to disable all the plugins, changing the themes back to default, changing the max file size back, and adding <code>define('WP_MEMORY_LIMIT', '1024M');</code> (and other values) to WP-config but none of it helped.</p>
  
  <p>Also tried to 'Update network', but I got an error - couldn't connect to host.</p>
  
  <p>Any ideas?</p>