title: PurgeIdleCellConnections causes application to freeze then crash
body: <p>My app keeps rapidly throwing this up at me until we run out of memory and hang:</p>
  
  <pre><code>purgeIdleCellConnections: found one to purge conn = 0x1ddde360
  purgeIdleCellConnections: found one to purge conn = 0x1dddb9a0
  purgeIdleCellConnections: found one to purge conn = 0x1e87d4b0
  purgeIdleCellConnections: found one to purge conn = 0x21b98a60
  purgeIdleCellConnections: found one to purge conn = 0x21baeae0
  purgeIdleCellConnections: found one to purge conn = 0x1dde92c0
  purgeIdleCellConnections: found one to purge conn = 0x21b3a3a0
  purgeIdleCellConnections: found one to purge conn = 0x21ce0a40
  purgeIdleCellConnections: found one to purge conn = 0x1e81b4d0
  purgeIdleCellConnections: found one to purge conn = 0x21987880
  purgeIdleCellConnections: found one to purge conn = 0x21994d50
  purgeIdleCellConnections: found one to purge conn = 0x21b463b0
  purgeIdleCellConnections: found one to purge conn = 0x1e81b2b0
  purgeIdleCellConnections: found one to purge conn = 0x1dde2130
  purgeIdleCellConnections: found one to purge conn = 0x1dd02cc0
  purgeIdleCellConnections: found one to purge conn = 0x21987130
  purgeIdleCellConnections: found one to purge conn = 0x1e89b610
  purgeIdleCellConnections: found one to purge conn = 0x21a7c5a0
  purgeIdleCellConnections: found one to purge conn = 0x219307e0
  purgeIdleCellConnections: found one to purge conn = 0x21b44240
  purgeIdleCellConnections: found one to purge conn = 0x21b6f290
  purgeIdleCellConnections: found one to purge conn = 0x219c1db0
  purgeIdleCellConnections: found one to purge conn = 0x1e81c5f0
  purgeIdleCellConnections: found one to purge conn = 0x21957890
  purgeIdleCellConnections: found one to purge conn = 0x21cd86f0
  purgeIdleCellConnections: found one to purge conn = 0x21cd6660
  purgeIdleCellConnections: found one to purge conn = 0x21b43140
  purgeIdleCellConnections: found one to purge conn = 0x21cd4400
  </code></pre>
  
  <p>Any idea what this is? I'm fairly new to iOS but I couldn't find anything on this.</p>
  
  <p>Hopefully somebody has seen this before.</p>