What does your directory structure look like? Where did you put bbPress, and where is WordPress? Does it look like this:
/var/www/htdocs/wordpress/wp-config.php
/var/www/htdocs/wordpress/bbpress/bb-config.php
Did you modify the wp-config.php file at all? Do you have access to error logs? A blank screen is likely a 500 Internal Server Error.
If you can’t see the sites, you have bigger problems than just integrated logins. You should be able to view the WordPress site and the bbPress forum without logging in.
