http://www.aopa.org/advocacy/articl...ge_test_revisions_surprise_scores_suffer.html
AOPA has engaged the FAA in response to reports that unannounced, significant changes in the question banks of at least three airman knowledge tests have dramatically increased failure rates.
Question banks affected by the changes include the Fundamentals of Instruction (FOI), Airline Transport Pilot (ATP), and Flight Engineer (FE) knowledge test. Test providers, universities and flight schools have reported significant increases in the number of failures since the changes were implemented. More than half of those taking the FOI knowledge test since the changes were implemented failed the exam.
There are also reports from flight training programs that previously correlated scores between practice knowledge tests and actual tests for the instrument rating have begun to diverge.