The Vaio shutdown problem
The Intel goof was easily programmed around several OSs ago. The false overtemperature interrupt is detected and ignored. Intel laid out the needed code in a white paper in June 2002. The document order number is 243887-041.
There is a real problem with components on the CPU daughter board that get fried due to a faulty heat sink design. These cause the computer to shut down randomly, and in extreme cases not even boot up.
The solution is the replacement of these Surface Mount Technology components, and unless you have the tools and training to do SMT rework, I do not recommend doing it yourself, because it requires considerably above average soldering technique and precision equipment. If you attempt it without solid prerequisites, you run a substantial risk of killing the processor board. :(