issue with whitespace in output stream corrupting document

I am having an issue with one byte of data corrupting my word document. It opens fine when I download from server, but when I force download from web the file is one byte larger and corrupted. Ive looked until I am blue in the face for the "extra" space.

Strangely enough on windows, if I click recover document comes out fine....

 public function DownloadDocx()
{
    $this->_extension = "docx";
    $args = func_get_args();
    $newName = trim($args[0]);
    ob_flush();
    if (!empty($newName)) {
        $fileName =$_SERVER['DOCUMENT_ROOT'] . '/wills/docs/' .$newName;
    } else {
        throw new Exception("Invalid document name");
    }
      if(strstr($_SERVER["HTTP_USER_AGENT"],"MSIE")==false) {
        header("Content-type: application/vnd.openxmlformats-officedocument.wordprocessingml.document");
        header("Content-Disposition: inline; filename=\"". $newName . '.' . $this->_extension."\"开发者_JAVA百科");
        header("Content-Length: ".filesize($fileName . '.' . $this->_extension));
     } else {
        header("Content-type: application/force-download");
        header("Content-Disposition: attachment; filename=\"". $newName . '.' . $this->_extension."\"");
        header("Content-Length: ".filesize($fileName . '.' . $this->_extension));
     }
     header("Expires: Fri, 01 Jan 2010 05:00:00 GMT");
     if(strstr($_SERVER["HTTP_USER_AGENT"],"MSIE")==false) {
      header("Cache-Control: no-cache");
      header("Pragma: no-cache");
     }

     readfile($fileName . '.' . $this->_extension);
}

After readfile($fileName . '.' . $this->_extension); add exit;.

If problem persists, try to add at begin of the function die( '.' );, run your script and look at page source if dot (.) is the first character.

Most common cause of this sort of problem by a long, long way is a whitespace character before <?php or after ?>.

Note that you probably don't actually need the closing ?> in a file that is pure PHP code, which helps avoid this problem.