Integrate WP into existing CMS – Conflicts!

Hi,

I try to integrate a running wordpress installation into my CMS. I started with simply inserting require('...path.../wp-blog-header.php') into my CMS at the position I want the blog to be displayed.
However, I get the following error: Fatal error: Call to undefined method stdClass::set_prefix() in D:\...my path...\wordpress\wp-settings.php on line 268

Somehow wordpress is unable to load the database properly (set_prefix() is a method of the wpdb class). Since my CMS uses some ‘magic’ methods of PHP like __autoload() etc, I suspect this to be the reason for the error. But I couldnt find any methods in WP that are also used by my CMS.

What I found out so far:
The $wpdb object isn’t initialized at all. When I call var_dump($wpdb) in wp-settings.php it says “NULL”. However at the bottom of wp-db.php it is set up properly (var_dump shows the content of the object).

I found on google someone that has a similar problem using cakePHP + WP. But what methods (that are apparently used by cakePHP and my CMS) cause the conflict?

Thanks for your help!

Best regards,
ms