Fatal error: Call to undefined method CI_DB_mysql_driver::get_where()

[eluser]plainas[/eluser]
I have no idea what can be triggering this error:

Fatal error: Call to undefined method CI_DB_mysql_driver::get_where()

Fatal error: Call to undefined method CI_DB_mysql_driver::get_where()

Here's the code where the error occurs:

Code:

$sqldata = array('tag' => $tag);
$query = $this->db->get_where('tags', $sqldata);

$tag is a string.

Can anybody give me a hint?

[eluser]Unknown[/eluser]
Make sure you have active record turned on in your database config.

Code:

// system/application/config/database.php
$active_record = TRUE;