title: Can't get Boost Thread pool on dual core ios device(iPhone4s, iPad2, etc)
body: <p>In my IOS app, i use a thread pool(Boost Thread) to download resource images.
  All build(including OTA build) except appstore build works fine.
  After investigating, the appstore build can't get Boost Thread pool ONLY on dual core ios device(iPhone4s, iPad2, etc).</p>
  
  <p>And it occurs only at the first time startup. After i kill and restart app, it works fine.</p>
  
  <p>Could somebody help figure out why?</p>
  
  <p>Can i make such assumption:  Boost Thread + Dual Core + Apple post-encryption(for OTA build works fine), that have all added up, led to the problem?</p>
  
  <p>Thanks</p>