That actually sounds like it might be the start of target panic. I used to do that a few years back, your mind is to worried about where the arrow will hit, and not concentrating on aiming. The inability to hold on target is a precursor to target panic. I might be wrong, but this seems all to familiar to me.Best of luck with fixin it buddy. If it is the last arrow, it is because you are fired up about your group and peeking. Ask me how I know that.

Shane