If Buddha stayed unanswered on this matter, why do his followers preach that soul doesn't exist?

Almost every Buddhist I've met sincerely believes in non-existence of self or soul. Especially, the vipassana practitioners say that *scanning* the body and finding no atman or *self* in it is proof that self doesn't exist. But what about the practitioner himself who is scanning or performing the vipassana? Doesn't that imply that he himself is the soul? Also, I found today that [Buddha](http://en.wikipedia.org/wiki/The_unanswered_questions) himself stayed unanswered on this matter: > The Buddha states that it is unwise to be attached to both views of having and perceiving a self and views about not having a self. So, how can you argue that soul doesn't exist when Buddha himself didn't deny it (or accept it either)? Are there any branches of Buddhism that *believes* in existence of soul?