Description:
------------
After setting up PHP4.3.10 my application stoped working with error message saying about error in one of PEAR files. 
After looking into code that caused error I figured out a very strange thing: the array_keys function gets as  parameter a valid array but returns NULL. I tried to reproduce the bug without using PEAR files but didn't succeed. So I will describe the issue using PEAR code.
File: PEAR/DB/dataobject.php (version 1.7.2) (DB_DataObject PEAR package)

P.S. I have no Zend debuger/optimizer/.... or any 3rd party extensions installed
php -v result:
C:\wwwroot\bug>php -v
PHP 4.3.10 (cgi-fcgi) (built: Dec 14 2004 17:47:59)
Copyright (c) 1997-2004 The PHP Group
Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies


Reproduce code:
---------------
795     if (is_object($from)) {
796        $table = $from->__table;
797        $from = array_keys($from->table());
798     }
$from->table() returns a valid array , but $from after assignment becomes NULL. 
If we modidfy the code in the following way:
795     if (is_object($from)) {
796        $table = $from->__table;
           $tmp = $from->table();
           var_dump($tmp);
797        $from = array_keys($tmp);
           var_dump($from)
           die('theend');
798     }
the result will be:
array(2) {
  ["id"]=>
  int(129)
  ["name"]=>
  int(2)
}
NULL
theend

moreover if we modify the code in another way:
      if (is_object($from)) {
         $table = $from->__table;
         $tmp = $from->table();
         $from = null;
         $from = array_keys($tmp);
      }
PHP crashes and Windows offers to send a report to Bill Gates :)