Hi Karl,
From what you've described, it sounds like you've taken at least 5 CATs last week - and that was NOT a good idea. The process of taking (and reviewing) a CAT requires a significant amount of energy and effort - and takes time to 'recover' from. This is one of the reasons why you typically shouldn't take more than 1 CAT per week. By taking so many CATs in such a short period of time, there's a reasonable chance that you experienced some 'burn out' - and that could help to explain your score on this recent Official GMAC CAT. In addition, there might be other issues based on how you took these CATs:
1) On what dates did you take each of these CATs?
2) Did you take the ENTIRE CAT each time (including the Essay and IR sections)?
3) Did you take them at home?
4) Did you take them at the same time of day as your Official GMAT?
5) Did you ever do ANYTHING during your CATs that you couldn't do on Test Day (pause the CAT, skip sections, take longer breaks, etc.)?
6) Did you ever take a CAT more than once? Had you seen any of the questions BEFORE?
Beyond those questions, I'd like to know a bit more about your timeline and goals:
1) What is your goal score?
2) When are you planning to apply to Business School?
3) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich