Would could possibly be the reasons why when setting a Session variable in a button click event, when it hits the Page_Load the session variable is null meaning it does not appear to exist. The IsPortBack in the Page_Load is true. There is nothing in the web.config file regarding sessionstate or anything to do with sessions.
If I just create a new web app project and do a session variable and all it seems to work so the configuration of IIS, machine.config seems ok in the new web app project there is nothing in the web.config either regarding sessionstate.
What could possibly cause this or am I just missing something?