It is possible. FSX is CPU intensive which could lead to you CPU getting hot, even more so if it is Overclocked as well. O/C CPU generates more heat than at the normal clock speed so IF that is the problem, it could be worth reducing the CPU clock seep just a bit. OR get a better cooling system like the Corsair H series.

I am seriously considering the Hydro Series™ H80 High Performance Liquid CPU Cooler as a way to OC CPU without the worry of it getting too hot. Whether I get a new i7 2600K CPU and motherboard first remains to be seen.

Mark