title: Convert a tuple to a numpy array corrupts the data
body: <p>Does anybody can explain what's going on here?</p>
  
  <pre><code>import numpy as np
  
  test1 = ((154L, u'D2'), (155L, u'D2'), (156L, u'D2'))
  print np.asarray(test1)
  </code></pre>
  
  <p>gives</p>
  
  <pre><code>[[u'15' u'D2']
  [u'15' u'D2']
  [u'15' u'D2']]
  </code></pre>
  
  <p>but with</p>
  
  <pre><code>test2 =((154L, u'SG2'), (155L, u'SG2'), (156L, u'SG1'))
  print np.asarray(test2)
  </code></pre>
  
  <p>we obtain</p>
  
  <pre><code>[[u'154' u'SG2']
  [u'155' u'SG2']
  [u'156' u'SG1']]
  </code></pre>
  
  <p>What happened to the long integer in test1</p>