Codeigniter session class doing a ton of identical queries every page load

[eluser]@li[/eluser]
My controllers are loading slowly. In order to investigate I turned on the profiler. In the profiler's output, I noticed that at the very start of the page, these queries are being run:

Code:

UPDATE `ci_sessions` SET `last_activity` = 1338996582, `user_data` = 'a:7:{(omitted);}' WHERE `session_id` = '093d065eb9253da9454efd2362cee404'



UPDATE `ci_sessions` SET `last_activity` = 1338996582, `user_data` = 'a:7:{(omitted);}' WHERE `session_id` = '093d065eb9253da9454efd2362cee404'



UPDATE `ci_sessions` SET `last_activity` = 1338996582, `user_data` = 'a:7:{(omitted);}' WHERE `session_id` = '093d065eb9253da9454efd2362cee404'



UPDATE `ci_sessions` SET `last_activity` = 1338996582, `user_data` = 'a:7:{(omitted);}' WHERE `session_id` = '093d065eb9253da9454efd2362cee404'



UPDATE `ci_sessions` SET `last_activity` = 1338996582, `user_data` = 'a:7:{(omitted);}' WHERE `session_id` = '093d065eb9253da9454efd2362cee404'



UPDATE `ci_sessions` SET `last_activity` = 1338996582, `user_data` = 'a:7:{(omitted);}' WHERE `session_id` = '093d065eb9253da9454efd2362cee404'



UPDATE `ci_sessions` SET `last_activity` = 1338996582, `user_data` = 'a:7:{(omitted);}' WHERE `session_id` = '093d065eb9253da9454efd2362cee404'

This is adding about 2 seconds of load time to all my pages. Why is it running these queries about 7 times? Where can I change it so it only runs them once and that's enough?