CI session and session ID

[eluser]haXis[/eluser]
Hello,

I have a cart database table with session column which represent the CI session_id.

My question is - is there any way how to recognize that the session_id changed?

Debug session action:

Code:

SELECT *
FROM (`tc_ci_sessions`)
WHERE `session_id` = '99c86bd7597f7e463750ab94dbadb9dc'
AND `user_agent` = 'Opera/9.80 (Windows NT 6.1; U; cs) Presto/2.5.22 V'  

UPDATE `tc_ci_sessions` SET `last_activity` = 1267785550, `session_id` = 'd99c65b60773945ee125bd112e84903a' WHERE session_id = '99c86bd7597f7e463750ab94dbadb9dc'

Without changing the session ID in a cart I loose him and I dont want that before 7200 seconds.