Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 17488)
+++ wp-includes/post.php	(working copy)
@@ -985,6 +985,9 @@
 
 		if ( $args->has_archive ) {
 			$archive_slug = $args->has_archive === true ? $args->rewrite['slug'] : $args->has_archive;
+			if ( $args->rewrite['with_front'] )
+				$archive_slug = substr( $wp_rewrite->front, 1 ) . $archive_slug;
+
 			$wp_rewrite->add_rule( "{$archive_slug}/?$", "index.php?post_type=$post_type", 'top' );
 			if ( $args->rewrite['feeds'] && $wp_rewrite->feeds ) {
 				$feeds = '(' . trim( implode( '|', $wp_rewrite->feeds ) ) . ')';
@@ -5236,4 +5239,4 @@
 }
 add_filter( 'wp_get_object_terms', '_post_format_wp_get_object_terms' );
 
-?>
\ No newline at end of file
+?>