janjan: A lot of temp monitoring software is using the wrong TjMax. Download RealTemp and see what it says. Here's some software temp testing of an E8400.

Run CPU-Z and make sure your core voltage isn't too high. Some Asus motherboards when the core voltage is set to AUTO get way too generous with additional voltage when you start to overclock which only creates extra heat. Most E8400 chips can run 3.6 GHz with about 1.20 volts and many of the better chips can do it with less than that.