In addition to the other problem reported on the "mark all topics" thread, i have experienced other various technical inconveniences with the site related to sessions and being remembered as logged in or not.
For example, i had acces to all the sections when i browsed
http://peakoil.com, but i was denied access to the private messages when i browsed
http://www.peakoil.com and i received an error message saying i'm not logged in.
Since cookies are kept separately for the 2 domains, this would be normal if i only logged in on peakoil.com and was browsing as a guest on
www.peakoil.com. However, i was seen as logged in on the
www.peakoil.com main page, it just popped the error message when clicking on "No New messages", and it asked me to log in again when i clicked on "Your Account".