Index: wp-includes/css/admin-bar.dev.css
===================================================================
--- wp-includes/css/admin-bar.dev.css	(revision 18302)
+++ wp-includes/css/admin-bar.dev.css	(working copy)
@@ -98,6 +98,8 @@
 	border: 1px solid #dfdfdf;
 	border-top: none;
 	float: none;
+	left: auto;
+	right: auto;
 }
 
 #wpadminbar .selected .shortlink-input {