Hey Andy,
That's definitely not the case.
I've used that method of search with other GNU/Linux distribution forums, and it has always worked.
Have you had that issue before?
The reason why I'm suggesting a move away from mailing lists is that it is a lot easier to follow threads on forums.
You have all the replies on the same page, compared to clicking on the link of each reply, realizing it doesn't have the answer, clicking another link and so on...
Furthermore it'll be easier to distinguish between contributors and users, which I think will be a necessity if we grow.