title: Magento: 500 Internal server error
body: <p>I have PHP as CGI installed server with magento.</p>
  
  <p>I keep getting the 500 internal server error on some specific pages.-</p>
  
  <ol>
  <li><p>When someone add items to cart and say checkout the error comes up on the screen and the page url is /checkout/onepage.</p></li>
  <li><p>When I login into admin site once again the error is there.</p></li>
  </ol>
  
  <p>I have given the 755 permission to all the required files and folders of magento.</p>
  
  <p>I can fix this error temporary by giving the permission to the root index.php file to 755. But after some time the error is still there and again I have give the permission of root index.php file to 755 to access the pages.</p>
  
  <p>How can I resolve this error permanently?</p>
  
  <p>My hosting server is 1and1.com</p>
  
  <p>Thanks.</p>