Hi, I've written a form element for drupal 5.x which, in it's #validate callback, converts a comma-seperated string into an array of ids. It uses the form_set_value() function to change the string value to an array. My element fails in multistep forms. The reason being that first the form is processed, then the $form_values which my call to form_set_value() affected is discarded (at the end of drupal_process_form()) then drupal_retrieve_form() is called again, this time passing in $_POST (this happens in drupal_get_form()). Because my call to form_set_value() affects $form_values and not $_POST, my changes are lost. I've noticed that if I also change the $_POST after I call form_set_value(), I can work around the problem: // Here's the call usually make: form_set_value($element, $items); // Here's the workaround that modifies $_POST: _form_set_value($_POST, $element, $element['#parents'], $items); For a number of reasons, I feel that call to _form_set_value() is hacky and does not belong in my code. However, it might be a reasonable addition to form_set_value(). If I were to submit that as a patch, any chance it would be committed? I'm not the only one who's had problems with form_set_value(). Most people find workarounds usually avoiding it entirely, but I have yet to find one for my case. For example, http://drupal.org/node/264743. Thanks, -Dave