Samburk:

The flying right elbow is a tough move to break because it feels like you are swinging very freely with a wide extension using this technique. This is very true and these are usually good things. The problem comes when you have to time the return of the elbow back to the right side during the transition. Your brain will be sensing that if you bring the right elbow and upper arm quickly back to the right side you will crash into it and disrupt the swing. Actually bringing the elbow back into the right side is what you need to accomplish (see any description of the "magic move"). I suspect your brain is getting the better and you are taking the arms well around the right hip on the downswing thus coming over the top in a big way. The faster the transition the more over the top. It does not really matter if the results are pulls or slices because neither are what you want.

Try swinging (and video taping if possible) keeping the right elbow tucked in more at the top. What you will be doing is keeping the elbows closer together which produces a more connected swing. With the flying right elbow the left and right elbows can be more than two feet apart at the top. Give yourself good extension going back to avoid pulling the club inside. Pulling the club too far inside can happen because you will be focusing on keeping the right elbow in to your side going back. Avoid this temptation and swing back freely away from the ball but as you begin to take the club to the top keep the right elbow pointing down toward the ground not pointing away from the right side of your body. You will need to turn agressively with your body through the ball but only after a smooth transition lead by your legs to deliver the club in the slot. By keeping your right elbow closer to your right side at the top, on the downswing it will already be close to where it needs to be tucked against your right lateral muscle. Remember that you are not going to feel the ball being hit so much with the arms but with the body and this is a good thing.

Best of luck