My bad, I forgot to put in some study tips. In my retake, my score went up three points. Not drastic, but definitely better. I know I have my basic knowledge of the sciences down, so I didn't bother re-reading the review books a second (third?) time, as it is a complete waste of time. I already know the organelles and how thermochem works - why read up on it again?
What I did different this time is that I focused entirely on practice problems and timing. I realized that the first time I took the MCAT, I ran out of time on almost every section. This time, I retook almost all the practice AAMC's and Kaplan practice exams all over again. Sure, I remembered the answers to some questions, but after taking a practice exam every morning, I got the hang of testing.
Second, I reviewed each and every physics and gen chem formula. These PDFs really helped me ace the PS section:
http://www.thinkmcat.com/DOWNLOADS.html
Download them, memorize them, take them everywhere you go. Make sure you know the difference between electric potential and electrostatic force yaddayadda, and their respective equations.
I remember reading this in a previous thread, but someone mentioned copy-pasting questions you got wrong on each practice test onto a powerpoint presentation, then reviewing each question as a slideshow. This strategy definitely helped me. All in all, practice makes perfect. Good luck.