I have this same problem and it is REALLY ANNOYING. If anyone knows how to solve this, I’d love to hear about it.
If I delete cookies it works exactly one time, then stops keeping track of which posts are new again. Oddly enough if I look at the boards from the office, it works like it is supposed to, but not from the house. I have also tried placing scorched3d.co.uk as a trusted site but that doesn’t solve the problem either.
Now that you mention it – it seems to me that it works for me at the office too, but not at home. Perhaps it’s a sign that we need to spend less time at home on the forums and more time at work on the forums. 😆
Point of interest: At work I’m running Win XP and IE, and at home I’m using Linux and Konqueror. I’ll try it with Firefox and see what happens.