camera acceleration issue

first at all, english isn't my first language, so sorry if it's bad.
when i move the camera sometimes it moves real fast and it's very annoying specially on shootouts. i tried to disable mouse acceleration from windows and didn't solve the problem, i only have this problem on Saints Row 2 (Steam version btw).
strange thing is, that i reinstalled the game and the issue wasn't there, but at the next launch it appeared again.
i didn't found a solution on the internet, so i hope someone help me here :(