Security Software

I'm having some trouble with SSO partner applications, when I login to a SSO protected application, the login works fine, but when I try to navigate to another application I'm presented with the login page again, the sso cookie seems to be working since clicking on the login button without entering the user credentials works. For example, I log in to portal and from there I navigate to a forms application that is on the same server and the same port (portal: https://apps.mydomain.com:4444/pls/portal --> forms: https://apps.mydomain.com/forms/frmservlet?config=app) I am presented with the login page and after clicking on the login button without entering any information everything works fine. This is happening for all the middle tiers that are connected to the same OID. Any ideas on what can be wrong on my configuration?