BUG with bbpress

Hello,
i post here because with this plugin, bbpress is blocked…

When i disable and reenable bbpress, is see ‘You do not have permission to access this page.’ but i’m the administrator.

When i go on http://mywebsite.com/forums when i’m administrator, i see forums with topics but ‘ERROR: You do not have permission to reply’.

When i go on http://mywebsite.com/forums when i have another role, i see Error 404 page.

Can you help me please ?

http://wordpress.org/extend/plugins/wp-user-frontend/