Dual montior - full screen problem

This is the problem i'm having now
I just started using dual screen, everything was fine

until i tried to fun games in full screen
the right most stuff in the main montior would shift a abit to the second monitor (to the right)
a second later, the game will automatically alt-tab itself out
i tried clicking the game, same thing, a second later, it pops itself back out

games in windowed mode works fine

this problem is really really annyoing, would be great if there is a solution

thanks!

btw, lastest drivers, using readon 3780x2

i just tested trying everyone resolution for a game, it finall worked for a certain resolution, but this will be annoying if i have to do this for every single game, any fixes?