Re: delete tables start over
It looks like you used wp_ (instead of bb_) as your table prefix, and WordPress was already installed, which means bbPress tried to install into the WordPress tables?
By default, WordPress uses these tables (in 2.7):
And bbPress uses these in the alpha version:
bbPress 0.9.0.* versions used different tables:
And when you integrate, bbPress uses the wp_users and wp_usermeta tables instead of its own bb_users and bb_usermeta.