Mysqli driver: trans_begin() gone in 3.0.3

Hi guys, 

I updated from 3.0.0 to 3.0.3 and all my manually handled transactions stopped working. Inspecting the driver implementations I found the following changes to the method:

3.0.0: 
public function trans_begin() { ... }

3.0.3: 
protected function _trans_begin() { ... }

is this intended? Am I supposed to derive from this class and implement my own driver or should I simply update all my code to call on the new methods?

I'm not sure what causes your problem, but the public function trans_begin() still exists in CI_DB_driver class (in system/databases/DB_driver.php)