Re: difficulty integrating wp/bbp
Check your database content via phpmyadmin for a
capabilities entry in wp_usermeta and, if it exists, delete it. Try the admin panel again.
No input file specified is a standard PHP error. Nothing to do with bb. From a quick google (I have no actual knowledge of this):
The basic issue was that PHP-as-CGI REALLY REALLY wants SCRIPT_FILENAME.
It ignores the command line. It ignores SCRIPT_NAME. It wants SCRIPT_FILENAME.
This very informative error message from PHP means that your web server, WHATEVER it is, is not setting SCRIPT_FILENAME.