Same result with a copy of the array.

Source array and the copy are modified.
Reproduce code:
---------------
$aTmp = array();
$oTmp = new stdClass();
$oTmp->id = 1;
$aTmp[] = $oTmp;
$oTmp = new stdClass();
$oTmp->id = 2;

$aTmp3 = $aTmp
foreach ($aTmp3 as $iKey => $oTest)
	$oTest->id = 'tea';

var_dump($aTmp, $aTmp3);

Expected result:
----------------
array(2) {
  [0]=>
  object(stdClass)#1 (1) {
    ["id"]=>
    int(1)
  }
  [1]=>
  object(stdClass)#2 (1) {
    ["id"]=>
    int(2)
  }
}
array(2) {
  [0]=>
  object(stdClass)#1 (1) {
    ["id"]=>
    int(1)
  }
  [1]=>
  object(stdClass)#2 (1) {
    ["id"]=>
    int(2)
  }
}
Actual result:
--------------
array(2) {
  [0]=>
  object(stdClass)#1 (1) {
    ["id"]=>
    string(3) "tea"
  }
  [1]=>
  object(stdClass)#2 (1) {
    ["id"]=>
    string(3) "tea"
  }
}
array(2) {
  [0]=>
  object(stdClass)#1 (1) {
    ["id"]=>
    string(3) "tea"
  }
  [1]=>
  object(stdClass)#2 (1) {
    ["id"]=>
    string(3) "tea"
  }
}

Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions.  Due to the volume
of reports we can not explain in detail here why your report is not
a bug.  The support channels will be able to provide an explanation
for you.

Thank you for your interest in PHP.

Objects are always passed by reference in PHP-5.