Hi tripledown,
GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. Assuming a similar 'swing' in how your CATs function, your 2 CAT score results show that you essentially performed the same each time (about 490 +/- a few points). You seem to understand this information, but it bears repeating. At this point in your studies, you still 'see' (and respond to) the GMAT in the same ways as you did when you took your first CAT. This is actually quite common in the early phase of one's studies; it takes time to practice/master the proper Tactics AND use those Tactics under realistic, timed conditions. On this CAT, how often did you use the Tactics that you've learned in the Course so far?
"Review" is an exceptionally important part of the GMAT training process; your ability to define WHY you're getting questions wrong is essential to defining the areas that you need to work on (and the specific things that you need to 'fix '). While a full Mistake Tracker would provide a lot more information, there are some basic questions that you should be able to answer (and the more EXACT you can be with your answers, the better):
After reviewing each section of this recent CAT, how many questions did you get wrong....
1) Because of a silly/little mistake?
2) Because there was some math/verbal that you just could not remember how to do?
3) Because the question was too hard?
4) Because you were low on time and had to guess?
5) How many Verbal questions did you 'narrow down to 2 choices' but still get wrong?
Since you're still in the early stage of your studies, you shouldn't worry about any subjects that you have not learned yet. However, there were likely some questions that you COULD have gotten correct (but didn't). Defining why you got THOSE questions wrong - and then working to eliminate those little errors - should help you to quickly pick up some points (and score higher on your next CAT).
GMAT assassins aren't born, they're made,
Rich