It's about thermal power of AMD <-> Intel. As you can see the problem is not the thermal power of the CPUs themselves (it's pretty much equal for main stream CPUs and much higher at P4 3GHz), but it's the hardware installation and the used CPU cooler. That's why most P4 are boxed and allready have a proper cooler and a heat spreader, which reduces the problem of wrong placed coolers.
So, you're right if you say many AMD PCs have heat problem, but IMO it's not the CPU thermal power which cause the problems. I know far too many people that upgrade their CPU and MB without using the Heat-conductive paste and then wondering why their PC crashes and/ot the wrong cooler
