Yes, that is especially frustrating but it is even more so when, after you have done your job of researching exhausitvely, you start a new thread. You explain your problem in detail, your specific environment, what you have tried, what your hunches are, and what threads you have already searched as dead ends. Someone doesn't bother to read your entire thread, does a quick google and finds "it is already solved" in the thread that just says "Nevermind, I fixed it" and they admonish you and point you to that thread. You reply that you already looked at that thread, that you said you looked at it in your root thread and that it doesn't answer the question. You don't get any response - not from the person that made the response (because they now realize they were to impatient when trying to point out your ignorance) and not from anyone else because said person is so respected by that group they assume it is you who is in fact the ignorant one.
Now THAT is frustrating.