Index: selector.js
===================================================================
--- selector.js	(revision 6529)
+++ selector.js	(working copy)
@@ -259,14 +259,14 @@
 var Expr = Sizzle.selectors = {
 	order: [ "ID", "NAME", "TAG" ],
 	match: {
-		ID: /#((?:[\w\u00c0-\uFFFF_-]|\\.)+)/,
-		CLASS: /\.((?:[\w\u00c0-\uFFFF_-]|\\.)+)/,
-		NAME: /\[name=['"]*((?:[\w\u00c0-\uFFFF_-]|\\.)+)['"]*\]/,
-		ATTR: /\[\s*((?:[\w\u00c0-\uFFFF_-]|\\.)+)\s*(?:(\S?=)\s*(['"]*)(.*?)\3|)\s*\]/,
-		TAG: /^((?:[\w\u00c0-\uFFFF\*_-]|\\.)+)/,
+		ID: /#((?:[\w\u00c0-\uFFFF-]|\\.)+)/,
+		CLASS: /\.((?:[\w\u00c0-\uFFFF-]|\\.)+)/,
+		NAME: /\[name=['"]*((?:[\w\u00c0-\uFFFF-]|\\.)+)['"]*\]/,
+		ATTR: /\[\s*((?:[\w\u00c0-\uFFFF-]|\\.)+)\s*(?:(\S?=)\s*(['"]*)(.*?)\3|)\s*\]/,
+		TAG: /^((?:[\w\u00c0-\uFFFF\*-]|\\.)+)/,
 		CHILD: /:(only|nth|last|first)-child(?:\((even|odd|[\dn+-]*)\))?/,
 		POS: /:(nth|eq|gt|lt|first|last|even|odd)(?:\((\d*)\))?(?=[^-]|$)/,
-		PSEUDO: /:((?:[\w\u00c0-\uFFFF_-]|\\.)+)(?:\((['"]*)((?:\([^\)]+\)|[^\2\(\)]*)+)\2\))?/
+		PSEUDO: /:((?:[\w\u00c0-\uFFFF-]|\\.)+)(?:\((['"]*)((?:\([^\)]+\)|[^\2\(\)]*)+)\2\))?/
 	},
 	attrMap: {
 		"class": "className",