Index: templates/default/bbpress-functions.php
===================================================================
--- templates/default/bbpress-functions.php	(revision 6909)
+++ templates/default/bbpress-functions.php	(working copy)
@@ -124,7 +124,7 @@
 		// Get and filter the bbp-default style
 		$styles = apply_filters( 'bbp_default_styles', array(
 			'bbp-default' => array(
-				'file'         => 'css/bbpress.css',
+				'file'         => 'css/bbpress' . $suffix . '.css',
 				'dependencies' => array()
 			)
 		) );