I dunno about the shutdown thing but you usally get that error when your fan is running below the warning limit set in the bios. Your temps are very good btw, I get up to 80 degrees on 100% load on my cpu
Go into your bios and find something like cpu fan limit and set it to 200RPM or none. I have the same cpu cooler and I would frequently get the same error because it was running below 600RPM.
