'not found in haystack' error in Zend

If you get a '%value%' was not found in the haystack' error when using select boxes in Zend, add the following to the form element:

$element->setRegisterInArrayValidator(false);

or directly when creating form:

$form->addElement('multiselect', 'elementname', array('RegisterInArrayValidator' => false));

Solution found at: http://stackoverflow.com/questions/991001/zendvalidatebetween-strange-error-message