[eluser]InsiteFX[/eluser]
If it is still not working then you have some thing wrong in your code. The MY_Session stops the update of the session if it is an ajax call.
I have a whole menu system that uses ajax and I have no problems, so take a look at what you are doing in your code. Some place you are over writing your session data.
If you are updating the same session variable then it will get over-written.
And just a note the page will not update for viewing variables unless there is a page refresh.
