Weird issue when flying in FSX. (Anyone had dual monitor problems?)

[Dragonmount 5]

I've posted recently of my startup issue with fsx. Which seems to have been solved by deleting the logbook. The last time I attempted to fly with fsx everything ran smoothly until the white box load screen, it did its typical no boarder loading, and I tried maximizing it which seemed to work once the flight was loaded, but whenever I unpaused the flight it froze and made a horrible sound, and my second monitor turned black, I couldn't think of any way of getting out of it without turning off my PC and turning it back on again. What would cause this? I've never had this happen in the history of using fsx. I've never even read about it.