i was going to respond to your other thread but got sidetracked.
which Kaplan tests are you taking? if you have pdf or paper tests that are 77 questions each in ps and bs, they're copyright 2003 and they're called practice tests 6-11, the ps is wicked tough and probably not representative of the real thing. if that's not the case all i can suggest is try doing speed drills on topics you find difficult. good luck.