problem with CI object in library used in extended core class

[eluser]Unknown[/eluser]
Hi there!

I'm trying to extend the Input class using "method overriding" and i am trying to use one of my libraries in this override.

My problem is that the library in question needs the CI object, but using:

$this->CI = &get;_instance();

gives me this error:

Fatal error: Class 'CI_Controller' not found in C:\....\system\core\CodeIgniter.php on line 231

is there any way around this?

Thanks!!