Franz, you brought up the reasons for why I wanted to write an addendum. It's a difficult choice because I can see how it could work both to my advantage and disadvantage. I think for the most part though, the schools I am applying to average the two scores regardless of the score increase. I copied and pasted this from the UCLA application:
"If applicable, please describe any circumstances that negatively affected the extent to which your academic record or standardized test scores reflects your ability to succeed in law school."
Generally, I think I understand what you guys are saying about the explanation vs. excuse thing. So would it be safe to say that it is not a good idea to mention stess, illness, family emergency, etc. but rather explain the score difference by discussing what I did differently to study for the second exam (is that what you meant by a "good reason/explanation")? Because I had thought about doing this, but the problem is I think my first score was a result of basic anxiety, and not lack of preparation. So I was thinking that if I did mention a change in study habits, the ad coms could look down upon that because they would think that I went into the first test unprepared. What do you guys think?