Warning: Call-time pass-by-reference has been deprecated

I got this error when enabling the module on PHP 5.1.16:
Warning: Call-time pass-by-reference has been deprecated - argument passed by value; If you would like to pass it by reference, modify the declaration of [runtime function name](). If you would like to enable call-time pass-by-reference, you can set allow_call_time_pass_reference to true in your INI file. However, future versions may not support this any longer. in /drupal/modules/cck/form_restore/form_restore.module on line 27