I can't load my model

[eluser]Buso[/eluser]
You need to load the class before extending it.

One way is loading the parent model but do it somewhere before.
Another way is setting __autoload() magic function to find your base model (or any other class you need, like base controllers if any) when required. A good place for this is your config.php file, because it is loaded at the very beginning of your application.

Also, have you set your error reporting to E_ALL? So you can see what's going on