Nate how relaxed are you before you begin photoreading? I only ask because it sounds like your conscious mind might still be quite active if you are concerned about losing the tangerine.
Just a thought. I know that when I worry about losing the tangerine then I constantly lose it.
(I think that Paul mentions on one of the tapes that after you have established the tangerine you don't have to worry about it anymore because part of your attention will naturally stay focused on that point.) Now I don't worry about it and it works out much better for me.