Ok, don't know if this helps but....
If I follow a link from my email about a PM notification, it seems to work every time. If I go to the main page (in a new window) after logging in from the PM link, there is no trouble. But if I try to go to the main page before using that PM link, it seems to fail almost every time.
IRC seems to be a write off though. It hasn't worked in probably well over a week now.