Hi,

changelanguage 2.1.0 has a problem on Contao 3.0.0. After install it, "Edit the setting of the article..." cause error. errllog contains:
Code:
[11-Nov-2012 17:09:33 Asia/Tokyo] PHP Fatal error:  Call to a member function findMainLanguagePageForPage() on a non-object in /data/share/contao3-kbug/system/cache/dca/tl_article.php on line 939
After a while, below change fix the problem and it dosen't make a side affect on Contao 2.11.6.

Code:
--- system/modules/changelanguage/dca/tl_article.php.orig	2012-11-11 12:31:17.000000000 +0000
+++ system/modules/changelanguage/dca/tl_article.php
@@ -49,13 +49,6 @@ $GLOBALS['TL_DCA']['tl_article']['fields
 class tl_article_changelanguage extends Backend
 {
 
-	/**
-	 * ChangeLanguage object instance
-	 * @var object
-	 */
-	protected $ChangeLanguage;
-
-
 	public function __construct()
 	{
 		parent::__construct();
Best regards.

P.S.
I've tested with PHP 5.4.8 and above change has no problem with PHP 5.3.17 environment.