调用未定义的方法Config :: getConfig（）

I'm testing the Flexpaper plugin on Windows XP running with XAMP, the issue is that it doesn't shows the pdf's, checking the php error log it says:

PHP Fatal error: Call to undefined method Config::getConfig() in C:\xampp\htdocs\PDFViewer\php\services\view.php on line 24

The folder structure is: (omitting irrelevant files)

htdocs/
    |->PDFViewer/
        |->php/
            |->admin_files/
            |->config/
                |->config.ini.win.php
            |->lib/
                |->common.php
                |->pdf2json_php5.php
                |->pdf2swf_php5.php
                |->config.php
            |->services/
                |->view.php

Snippet of code of view.php

require_once("../lib/common.php");
require_once("../lib/pdf2swf_php5.php");
require_once("../lib/swfrender_php5.php");
require_once("../lib/pdf2json_php5.php");

Snippet of code of pdf2json_php5.php

require_once("config.php");
require_once("common.php");

Snippet of code of pdf2swf_php5.php

require_once("config.php");
require_once("common.php");

Snippet of code of swfrender_php5.php

require_once("config.php");
require_once("common.php");

And before you ask, yes, config.php do have the getConfig method

Edit: Added the config.php

<?php date_default_timezone_set('America/New_York'); ?>
<?php
class Config{
  protected $config;

    public function __construct()
    {
        if (!defined('ROOT')) {
            define('ROOT', dirname(dirname(dirname(__FILE__))));
        }

        if (!defined('APP_DIR')) {
            define('APP_DIR', basename(dirname(dirname(__FILE__))));
        }   

        if( PHP_OS == "WIN32" || PHP_OS == "WINNT"  )
            $this->config = parse_ini_file($this->getConfigFilename());
        else
            $this->config = parse_ini_file($this->getConfigFilename());
    }

    public function getConfigDir(){
        if( PHP_OS == "WIN32" || PHP_OS == "WINNT"  )
            return dirname(__FILE__) . '\\..\\config';
        else
            return dirname(__FILE__) . '/../config'; 
    }

    public function getConfigs(){
        return $this->config;
    }

    public function getConfig($key = null)
    {
      if($key !== null)
      {
        if(isset($this->config[$key]))
        {
          return $this->config[$key];
        }
        else
        {
          return null;
        }
      }
      else
      {
        return $this->config;
      }
    }

    public function setConfig($config)
    {
      $this->config = $config;
    }

    public function getDocUrl(){
        return "<br/><br/>Click <a href='http://flexpaper.devaldi.com/docs_php.jsp'>here</a> for more information on configuring FlexPaper with PHP";
    }

    public function getConfigFilename(){
        if( PHP_OS == "WIN32" || PHP_OS == "WINNT"  )
            return ROOT . '\\' . APP_DIR . '\\config\\config.ini.win.php';
        else
            return ROOT . '/' . APP_DIR . '/config/config.ini.nix.php';
    }

    public function saveConfig($array){
        $this->write_php_ini($array,$this->getConfigFilename());
    }

    function write_php_ini($array, $file)
    {
        $res = array();
        foreach($array as $key => $val)
        {
            if(is_array($val))
            {
                $res[] = "[$key]";
                foreach($val as $skey => $sval) {
                    $sval = str_replace("\"","\\\"",$sval);
                    $res[] = "$skey = ".(is_numeric($sval) ? $sval : '"'.$sval.'"');
                }
            }
            else {
                $val = str_replace("\"","\\\"",$val);
                $res[] = "$key = ".(is_numeric($val) ? $val : '"'.$val.'"');
            }
        }
        $this->safefilerewrite($file, implode("
", $res));
    }

    function safefilerewrite($fileName, $dataToSave)
    {   
        $dataToSave = "; <?php exit; ?> DO NOT REMOVE THIS LINE
" . $dataToSave;

        if ($fp = fopen($fileName, 'w'))
        {
            $startTime = microtime();
            do
            {  
               $canWrite = flock($fp, LOCK_EX);

               // If lock not obtained sleep for 0 - 100 milliseconds, to avoid collision and CPU load
               if(!$canWrite) usleep(round(rand(0, 100)*1000));
            } while ((!$canWrite)and((microtime()-$startTime) < 1000));

            //file was locked so now we can store information
            if ($canWrite)
            {            fwrite($fp, $dataToSave);
                flock($fp, LOCK_UN);
            }
            fclose($fp);
        }else{
            throw new Exception('Cant write to config ' . $fileName);
        }

    }   
}

Modify the code snippet of view.php into:

$ds = DIRECTORY_SEPARATOR;
require_once("..{$ds}lib{$ds}common.php");
require_once("..{$ds}lib{$ds}pdf2swf_php5.php");
require_once("..{$ds}lib{$ds}swfrender_php5.php");
require_once("..{$ds}lib{$ds}pdf2json_php5.php");

Looks like I've made it work after adding C:/xampp/htdocs to the include_path variable in php.ini, and then just modified the require_once functions.

require_once section in View.php looks like:

require_once("PDFViewer/php/lib/common.php");
require_once("PDFViewer/php/lib/pdf2swf_php5.php");
require_once("PDFViewer/php/lib/swfrender_php5.php");
require_once("PDFViewer/php/lib/pdf2json_php5.php");

And the same for pdf2swf_php5.php, swfrender_php5.php and pdf2json_php5.php.