Method RemovePersistentVar doesn't work for Guests

In-Portal has 2 session types:

• one that stored user-related data until he perform logout or closes browser window
• other (persistent) that holds data between user login/logout times

We use current user ID to store data in persistent session. All non logged in users share same ID - "-2". To prevent persistent session data to be mixed we store persistent session variables into regular session table and they will be deleted once user closes browser window.

All seems ok, but there is a problem with data deletion from persistent session for non logged in users (guests) - it doesn't work.