Codeigniter2 executing query on wrong database.. bug? - php

Question

I know CodeIgniter 2 pretty well and now I have a weird bug with an existing project and I can't figure it out.
$this->db->flush_cache(); // Just to be sure
echo $this->db->database; // Displays "database_A"
$query = $this->db->get('table_X');
Then I get the error:
A Database Error Occurred
Error Number: 1146
Table 'database_B.table_X' doesn't exist
SELECT * FROM (`table_X`) WHERE `account_name` = 'bob'
Filename: /home/naturbl9/public_html/app/models/my_model.php
Line Number: 132
You can clearly see that echoing the currently used database displays "database_A", yet CodeIgniter is trying to execute a query in "database_B" that is used somewhere else (and used with a different name on top of that! Not "db"). If I set "pconnect" to false, the issue doesn't occur however..
database.php config:
(database_B is loaded by using the same config but changing $db['default']['database'] dynamically to "database_B"):
$active_group = 'default';
$active_record = TRUE;
$db['default']['hostname'] = 'localhost';
$db['default']['username'] = 'username';
$db['default']['password'] = 'password';
$db['default']['database'] = 'database_A';
$db['default']['dbdriver'] = 'mysql';
$db['default']['dbprefix'] = '';
$db['default']['pconnect'] = TRUE; // If set to false, the bug doesn't occur!
$db['default']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = '';
$db['default']['char_set'] = 'utf8';
$db['default']['dbcollat'] = 'utf8_general_ci';
$db['default']['swap_pre'] = '';
$db['default']['autoinit'] = TRUE;
$db['default']['stricton'] = FALSE;