Well, I'm not an expert, but if you only answered 45-47 questions on the Biological Sciences test and got a 10, I think you basically got all that you did correct, which means you do know your stuff. I think you should take it again, if possible, because if you took some practice tests under timed conditions and figured out how to pace yourself, you would do AWESOME. When I started studying for the MCAT, I wasn't fast enough either...but I took about 4-5 timed practice tests and managed to improve my bio/phys scores each by 5-6 points. (I was able to finish all of the questions, but it sounds like you'd only have to answer 50-60 to get 10+ on the science sections.)
One thing that helped me speed up is that I stopped spending a ton of time reading the passages themselves...I skimmed for a general idea, then looked at the questions, and referred to the passage when necessary to answer them. Also, I started with the "free-standing" questions first...there are usually 3-4 clusters of them, and one is at the end. They were easy points for me, and I didn't want to run out of time before I got to them. Maybe you already do that stuff...just thought it might be helpful.
Also, if you haven't applied yet, as you mentioned in one of your posts, it seems like you would be able to take the test in April and be right on schedule to apply for 2001. It can't hurt to try it another time, and it might be a big help in strengthening your application.
Like I said, I'm no expert, but I hope this is helpful to you. Good luck!