Graphics card/cpu overheating?

Core i7, Nvidia gt525m, NO OVERCLOCKING.....
very often, (especially with payware scenery), screen starts going postal with flashing black areas that make flying a hair short of impossible.
Is this overheating or is it one of the many nuances of FSX?
very often, (especially with payware scenery), screen starts going postal with flashing black areas that make flying a hair short of impossible.
Is this overheating or is it one of the many nuances of FSX?