Great, sounds like your gfx card is fine. So I am back to thinking driver top of the list.
Any reason why you wouldn't want to try the 182.50?
I only ask because I have tried nearly every one and for the 200 series cards, I can't find a better one for overall compatibility. Pretty much all others, past the 185.85 cause me some sort of issue in some game or another. However, the 182.50 is golden. It works perfectly in eveything, including FSX. This is with Antialiasing OFF in the FSX menu.
If you have the box for Antialiasing ticked, try it unticked. But I don't think that is what is wrong.
I believe you may just be having issues with the newest drivers, maybe.
So, unless you have a reason for needing the newest NV drivers, I would seriously consider trying the 182.50-185.85 (182.50 is best for me).
Remember, this driver may be a year old, but it is two and half years newer than FSX is

I always uninstall drivers through device manager then restart the pc before putting new ones in... always been a habit of mine

I have a feeling I may have cured it, I have gone back to the up to date Nvidia Drivers as they give me atleast 10% performance incrase in the game from 195.62 , then decided to lower my system clock speed starting with the DRAM, Lowering this from 1950 to 1800 Seems to have made a difference, so far I have not had it back but we will see as only time can tell