Used to happen to me all the time. I'd quit the game and next time I start all my graphics wouldn't be reset, they would just change themselves, AA would turn off, go from high to low, low to high etc and sometimes all my controls and sensitivity would reset itself, but it seems to have settled now I just clear the shader cache, keep them to how I want and leave it as that, I think it was where I overclocked my CPU I know it sounds weird but that gave me all sorts of problems, BSOD EVERY time I played, crashes, and the control and graphic reset, then I underclocked a bit, ran Prime95 to make sure it's stable and get no problems at all- so if you overclocked CPU or GPU try stock clocks see if it still happens