PHP4 to PHP5 migration with E_STRICT

Hi, I'm migrating a web application written for PHP4 to PHP5. I've turned on E_STRICT to have a detailed look at all the code thoroughly. I have a number of 'Notices' and 'Strict Standards' messages appearing now. I don't consider myself a PHP guru by any means so I'm seeking help with understanding these messages and how to fix the code. One of the messages is: "PHP Strict Standards: Only variables should be assigned by reference in" This is for a class SPControlPanel with a method function getContentTypes(&$db) { $tabledata = array(); $sql = "select contenttype.* from contenttype"; return $db->queryAll($sql, true); } The warning is for this segment of code below which is another method in the same class (marked with comment // this line): function getCategoryTypes(&$db) { $tabledata = array(); $myContentTypes = &SPControlPanel::getContentTypes($db); // this line foreach ($myContentTypes as $key => $data) { if ($data['iscategory']) $tabledata[] = $data['contenttype']; } return $tabledata; } There are many more methods making assignments in a similar way in this class and in other classes throughout the code. I'm not sure of the best way to re-code this to resolve the E_STRICT warning. Any help is much appreciated. Regards, Tom