I received a very similar error (something about the database and needing to try to reinstall) when trying a fresh install and integrating wordpress at the same time. I retried it a few times – each time it would fail, and if I tried to access the forum location it would bring me to the installation script again.
Eventually I went through the installation without integrating wordpress and I that’s what ultimately worked. I then went through the wordpress integration after the install.
Latest wordpress & bbpress, on Linux, PHP 5.2.5, MySQL 4.1.22.