Sounds like an error in the php that is handling the form submission, not the select element.

<script type="text/javascript">
function header_title_id_OnChange()
{
    document.forms[0]["form_special_action"].value = "MODIFY_FEED_SELECTED";
    this.forms[0].submit();
}
</script>

<SELECT onChange=\"header_title_id_OnChange();\" ID=\"header_title_id\" 
NAME=\"form_header_title_id\"> 
<OPTION VALUE = \"\"></OPTION>"; 
/*****options filled with info from db******/
</SELECT>