I was able to reproduce your problem by deleting the eastdulwichforum.co.uk phorum_session_v5 cookie from my computer. I think its absence is the most likely cause. It might have happened if your browser configurations were recently changed, eg not to accept cookies, or to delete them at the end of each internet conection. Or it could have come to the end of its one-month life and got deleted automatically. But in that case I'd expect your situation to have beeen back to normal after your next login.
If you do want to actually check cookies and settings, you can probably do so via a Privacy menu item within Preferences or Options somewhere in your browser main menus.
I'm incidentally curious, about why people want to be always logged in. I tend to do so only when I want to post or to access PMs, and then I logout again.
Edited 1 time(s). Last edit was june 16, 12:52pm by ianr.