Description:
------------
This Code in PHP 4 running is ok, But in PHP5 Display "XML error: Invalid character at line 2", Why??

Reproduce code:
---------------
function makeTree($XML_FILE = ""){
		if(get_magic_quotes_runtime()){
			set_magic_quotes_runtime (0);
			$mq = 1;
		}
    $this->parser = xml_parser_create();
    xml_set_object($this->parser, &$this);
    xml_set_element_handler($this->parser, "startElement", "endElement");
    xml_set_character_data_handler ( $this->parser, "dataElement");
    if($XML_FILE){
      if (!($fp = fopen($XML_FILE, "r"))) {
        die("Could not open XML file");
      }
    }
    else{
      if (!($fp = fopen($this->file, "r"))) {
        die("Could not open XML file");
      }
    }

    while ($data = fread($fp, 4096)) {
    	$ffile=xml_parse($this->parser, $data, feof($fp));
      if (!$ffile) {
        die(sprintf("XML error: %s at line %d",
                    xml_error_string(xml_get_error_code($this->parser)),
                    xml_get_current_line_number($this->parser)));
      }
    }
    xml_parser_free($this->parser);
		if($mq){
			set_magic_quotes_runtime (1);
		}
    return $this->displayTree();

  } // end makeTree()


//----------------------------------------------------------------------------------------
  function makeTreeText($XML_TEXT = ""){
		if(get_magic_quotes_runtime()){
			set_magic_quotes_runtime (0);
			$mq = 1;
		}
    $this->parser = xml_parser_create();
    xml_set_object($this->parser, &$this);
    xml_set_element_handler($this->parser, "startElement", "endElement");
    xml_set_character_data_handler ( $this->parser, "dataElement");

    if($XML_TEXT=="")
    {
        die("XML TEXT is empty!");
    }

    $POS=0;
    $LEN=strlen($XML_TEXT);
    while ($data = substr($XML_TEXT,$POS, 4096)) {
      $data=str_replace("\0","/0",$data);
      $data=str_replace("&","&",$data);
      $cdata=xml_parse($this->parser, $data, 0);
      if (!$cdata) {
        die(sprintf("XML error: %s at line %d",
                    xml_error_string(xml_get_error_code($this->parser)),
                    xml_get_current_line_number($this->parser)));
      }

      $POS+=4096;
      if($POS>=$LEN)
         break;
    }
    xml_parser_free($this->parser);
		if($mq){
			set_magic_quotes_runtime (1);
		}
    return $this->displayTree();

  } // end makeTree()