What type of quiver do you have on your bow? (ie: detachable or two piece# of arrows)

I also shoot a PSE and have found their two piece quivers to be much better then the detachable ones. Reason being is the two piece fits more snug against the bow.

I agree grip could be a problem. Don't grip the bow, just let it rest in your crook of your hand and let your fingers rest gently. Not gripping. The sling will catch your bow if it jumps out of you hand. By not gripping the bow your hand the bow should be free of torque that may be introduced by your hand.