Extending CI_Config class problem

[eluser]gigowski[/eluser]
[quote author="Michael Wales" date="1198151387"]I'm thinking, since the native Config class is loaded by default - if you just create a file named MY_Config in /applications/libraries/ it would be loaded automatically.

Just like, if I created MY_Validation in /application/libraries/ it would be loaded automatically when I called $this->load->library('validation')[/quote]

When I did that I received the following error:

Fatal error: Call to undefined method: ci_config->db_config_fetch() in /homepages/42/d187750613/htdocs/lilcharacters/system/application/controllers/shop.php on line 8

I'm just going to change the MY_Config class so that it doesn't need to be extended form the core config class. I was just using the example I found in the wiki for making a database config. If anyone can think of why this wouldn't work, I'm still interested.