title: Prestashop DB doesn't work after long time
body: <p>I'm making prestashop xml import system and have trouble. I use simplehtmldom to read xml file. It's big, so it takes few minutes to read it. After reading, prestashop's Db class doesn't work. Before reading it works ok. Maybe I should change some limits? Tried with maximum_execution_time and so on, it doesn't give me any error, only 500 Internal Server Error, but script still works all time needed. Script works ok, all time, just Db class not working. Thanks :)</p>
  
  <p>Edit: I just tried to check for how long it works, so about 510 seconds, then db stops working.</p>