title: Magento version upgrade issue - Integrity constraint violation - mysql4-install-1.4.0.8.php
body: <p>I receive the following error when I tried to upgrade my Magento version from 1.4 to 1.7.
  Please help</p>
  
  <p><strong>Error in file:</strong> "/home/public_html/app/code/core/Mage/XmlConnect/sql/xmlconnect_setup/mysql4-install-1.4.0.8.php" - SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '3-thumbnail' for key 'entity_type_id'</p>
  
  <pre><code>Trace:
  0 /home/public_html/app/code/core/Mage/Core/Model/Resource/Setup.php(390):
  Mage::exception('Mage_Core', 'Error in file: ...')                                                                                    
  
  /home/public_html/app/code/core/Mage/Core/Model/Resource/Setup.php(276):
  Mage_Core_Model_Resource_Setup-&gt;_modifyResourceDb('install', '', '1.6.0.0')
  2 /home/public_html/app/code/core/Mage/Core/Model/Resource/Setup.php(240):
  Mage_Core_Model_Resource_Setup-&gt;_installResourceDb('1.6.0.0')
  3 /home/public_html/app/code/core/Mage/Core/Model/Resource/Setup.php(161):
  Mage_Core_Model_Resource_Setup-&gt;applyUpdates()
  4 /home/public_html/app/code/core/Mage/Core/Model/App.php(363):
  Mage_Core_Model_Resource_Setup::applyAllUpdates()
  5 /home/public_html/app/code/core/Mage/Core/Model/App.php(295): 
  Mage_Core_Model_App-&gt;_initModules()
  6 /home/public_html/app/Mage.php(596): Mage_Core_Model_App-&gt;run(Array)
  7 /home/public_html/index.php(82): Mage::run('', 'store')
    8 {main}
  </code></pre>