[eluser]Bas Vermeulen[/eluser]
Hi, I'm using it with CI 2.1.0 stable release, did not test with the latest develop but yeah should work.
In the config file I provided you can set the name of the session in which the user_id is stored:
$config['user_id'] = 'user_id';
Not sure which name Tank_auth uses cause I never used that, check it out and change the config file if needed, after that it should work perfect....