Well my system is running extremely slow - perhaps it is casued by the cpu throttling down? However it is running so slow that I suspect it is running at like 10% of normal speeds. Sometimes the system simply shuts down - but it sounds like this is also related to temps.
I'll try remounting the heat-sink and give it a bit of fresh paste
Thanks for all the great answers - I'll give best answer to proto - because he is new here - like me