Yes, it's very frustrating trying to study for the exams when the study guides are wrought with errors and contradictions. I wish those things were peer reviewed. However, these SSC QOTD, along with the peer discussions, keeps me on my toes :-)
True Story: The exam questions are filled with contradictions and odd errors also. They are peer reviewed (no really) a lot like these questions are. We would sometimes agree to leave in a "bad" question. One or two individuals would bother or Flame the rest of the panel until frustration, instead of logic, made the decision. That is why I have always recomended the use of "study guides" to anyone taking the certification tests.
IMHO: The best ones out there are Troy...