The auto-aim automatically drags the reticle in the direction of an enemy in your LoS when fine aiming. Most of the time you don't really notice it, but the number of times I've set up a shot on a captain only to have it pulled away at the moment I fire because a dreg chose that moment to run in front (without actually obscuring my shot on the captain in the first place) infuriates me. Especially since the auto-aim only drags a short distance, so half the time the shot misses the dreg as well, making the shot a complete waste.

Ya know, i have never noticed this either? I have never had my sights pulled off a target nor have i had a grenade track to a closer target. So i am wondering if i am doing something wrong?

Next chance you get, aim at the mobs that spawn in crotas crystal chamber while the glass is up and try not to move your stick. Your gun will follow the acolytes quite a bit automatically. Hence, too much auto aim.