I have created a single-sign-on system for our Oracle APEX applications, roughly based on this tutorial:

http://www.oracle.com/technology/oramag/oracle/09-may/o39security.html

The only difference is that my master SSO login is in Perl, rather than another APEX app. It sets an SSO cookie, and the app can check if it's valid with a database procedure.

I have noticed that when I arrive in the morning, the whole system doesn't work. I reload a page from the APEX app, it then sends me to the SSO page because the session was expired, I logon, and get redirected back to my original APEX app page. This usually works except first thing in the morning. It seems the APEX session is expired. In that case it seems to find the session, but then refuse to use it, and sends me back to the login page.

I've tried my best to trace the problem. The "wwv_flow_custom_auth_std.is_session_valid" function returns true, so I'm assuming the session is valid. But nothing works until I remove the APEX session cookie. Then I can log back in easily.

Anybody knows if there is another call that would tell me if the session is expired or not?

Thanks