Usually, when I log on to forums I stay logged on until I use another computer (e.g. going from home to work), then logging on to the 2nd automatically logs me out from the 1st. Over the last couple of days, despite only using my home laptop I find that I'm being logged out, maybe after as little a a couple of hours?

Either something has changed with the site, or someone has hacked my account and is logging on as me elsewhere.

[Goes to change password]

No. Have you changed security settings on your machine with respect to cookies? Has there been a software update to your machine that might have re-set stuff? When you log in, there's probably a "remember me" option - has that got unset?

My work computer did this - essentially, every time I visit the site in a new IE session, I have to log in again. Don't know what they changed to cause it, but it happens at other websites too. The problem with fiddling with the settings on a work computer is that they'll just fiddle them back in the next maintenance update