Matt Williams has a new post to his blog with his own fix to a problem he was having with his CodeIgniter application - the continuous session logouts.
For weeks I tolerated the annoyance of CodeIgniter's Session library logging my out continuously, saying to myself "I works...kind of...I'll fix it later". Eventually the problem started affecting AJAX method calls, large file uploads and simple CRUD operation forms so I began trawling the internet for a fix. After hours and hours, I found that there was no _reliable_ fix to the database sessions library and that the answer was, DON'T USE DATABASES.
The code for the library he found to help with the problem - CI_Native_Session - is included in the post (as written by Dariusz Debowczyk). It uses the native PHP session handling to keep track of the data rather than using a database table to persist users. You can see a demo of it here.