Question: I'm using Codeigniter 1.7.2 with the [OBsession](http://bleakview.orgfree.com/obsession) library to handle sessions and store them in a database. The app I'm working on consists of a domain (the one with CI) that acts as a service (don't know if this is the correct terminology). Other sites include a JavaScript file from that domain and from there, make an AJAX call to the CI domain. If the site doesn't have a session id, the CI domain returns the one created from that call and then the JS on the site sets a cookie with that session id. From then on, if the site makes any calls to the CI domain it includes that session id in order to identify itself.

This works on every other browser (Mac and PC versions) except for Safari and all Internet Explorers. In Firefox for example, I can see the initial session id get set in the client cookie and in the database and I can make as many calls as I want and as many page refreshes and it still has the same session id in the cookie and database. For Safari, on every page refresh I can see new sessions getting added to my session table.

Any ideas on what is going on here?

Answer: 
Safari and Internet Explorer (with medium security level) does not accept 3rd party cookies by default. A Google search brings:

<http://squeeville.com/2010/02/03/third-party-cookies-in-safari-internet-explorer/>

Hope this helps.
search for `session_start()` and paste the logic arround this function...