Does it only happen if you run BVE 4 in full screen but not in windowed mode?
It happens to me as well from time to time and no amount of graphics card update could solve it.
Edit: I remembered that not so long ago I had played an online game and it restarts in the middle. Upon checking the game's forum, they said its soemthing to do with a "memory leak". Although Im not very good the the programming side of softwares, I wonder if it would be cause.