Streamreader error using bbpress

I’ve installed bbpress 0.73 and i integrate it with wordpress also in styles.
I add <?php require_once(‘/Path to wordpress/wp-blog-header.php’) ?> for use “get_header”, or “get_footer” in bbpress templates.

Now i discover that it’s incompatible with BBLANG because if i try to set it on it_IT (my language) i get this error Fatal error: Cannot redeclare class streamreader in /…./forum/bb-includes/streams.php on line 26

Anyway if i remove the first lines i added in config.php the language work correctly but i cannot use “get_header” “get_footer” in bbress template.

it’s a wp-blog-header fault?

Anyone can help me ?