Over on SO, I upvoted a question about two hours ago.
But now, whenever I view it, I am logged out.
Ok sorry all, seems like this must be some sort of strange caching issue. Must be at the ISP (I had tried flushing my browser cache), as viewing the question from home works fine (I was having the issue from work)... i.e. I am not logged out when viewing the said question.
I will try again at work tomorrow and post results...still seems pretty strange though because the last time before the issue occurred I hit the page was to upvote the question so I was obviously logged in.