title: CWInterface returning no data
body: <p>I try to collect some information about the current state of the CWInterface(connected bssid, available access points...) and send them periodic (every 5-10 sec) via udp to a server.</p>
  
  <p>My Problem is that after some time (between 30 and 50 min in some tests with different collection/sending interval) the CWInterface stops returning data.</p>
  
  <ul>
  <li>[CWInterface interface] returns nil </li>
  <li>[CWInterface interfaceNames] returns a NSSet with 0 entries </li>
  <li>[[CWInterface interface] scanForNetworksWithSSID:nil &amp;error] also returns a NSSet with 0
  entries</li>
  </ul>
  
  <p>What am I doing wrong?</p>
  
  <p>I'm totaly out of ideas...</p>