Well, I don't know if this will address your situation, but I've had repeated blue screens caused by the CPU overheating. Since this was on my laptop, HP dv7, which has a VERY poor design for cooling, I got one of those CoolMaster laptop fans and the problem went away!
Maybe speedfan is causing your CPU to run hot? If you've got a desktop, clean the CPU heat sink and make sure it's well ventilated. You might consider a larger CPU cooling apperatus of some sort.
These are just my thoughts; hopefully they will help...
Russ