In my options i have set ADS sensitivity down to 0 and it is still too high making aiming whilst looking down the sights near impossible, the tiniest of motions makes the crosshair jerk wildly. I am currently using a Microsoft Comfort Optical Mouse 3000. I find that in general all sensitivity default levels are much too high and have to turn most of the sensitivities down to <2 in order for the game to be controllable.
Have you checked your Windows settimgs, iit is generally considered best to leave this at '6" and check you have no mouse acceleration enabled.
Yes i have, mouse accel is of and its midway in windows. Other FPS games are fine but planetside is unplayable ADS since the latest update.