>Notice the difference in search term?
Once again, you keep missing my point. I will not make it again after this, so here goes one last time:
This should be a clear option like nearly every other website with a forum does. Once again, look at my link. It shows that I am by far not the only person who has wasted time trying to find a forum specific search.
Simply put a field in the header area somewhere with text that says "Forum Search" or continue to have a poor UI that frustrates (and loses) users who don't have time to waste figuring out something that is an industry standard everywhere else.
It's a bad user interface.