What are the exact steps required for a cookie to persist after a browser is closed? At the moment I have:
createPersistentCookie set to tru
A persistent forms authentication cookie should not be discarded when the browser closes. It stays valid for the timeout value defined in the web.config.
However, some browsers can be configured to discard all cookies at the end of a session - you may want to check the settings of your browser (FireFox: Tools - options - privacy).