I sort of find the same with the practoce tests to be honest.
I read the ms-press books and watch the cbt nuggets videos, and I'm still suprised at how much I learn by doing the practice tests. Don't worry if you get the questions wrong, that's why they're practice tests! as long as you read the explanation as to why your answer was wrong and the other(s) are right, you'll be fine.
Paul Thomas
Network+ - Passed
70-210 - Passed
70-290 - Passed
70-291 - Passed
70-293 - Passed
70-294 - Passed
70-284 - Working Towards