Index: bbp-includes/bbp-general-functions.php
===================================================================
--- bbp-includes/bbp-general-functions.php	(revision 2916)
+++ bbp-includes/bbp-general-functions.php	(working copy)
@@ -745,6 +745,12 @@
 
 		// It is a user page (most probably), we'll also check if it is user edit
 
+		if ( !is_numeric( $bbp_user ) ) {
+			$bbp_user = get_user_by( 'slug', $bbp_user );
+			if ( is_object( $bbp_user ) )
+				$bbp_user = $bbp_user->ID;
+		}
+
 		// Create new user
 		$user = new WP_User( $bbp_user );