Added some additional checks to make sure that the correct methods are being...

Added some additional checks to make sure that the correct methods are being used in IE on XML documents.

src/selector.js

@@ -655,15 +655,15 @@ try {
 	// The workaround has to do additional checks after a getElementById
 	// Which slows things down for other browsers (hence the branching)
 	if ( !!document.getElementById( id ) ) {
-		Expr.find.ID = function(match, context){
-			if ( context.getElementById ) {
+		Expr.find.ID = function(match, context, isXML){
+			if ( typeof context.getElementById !== "undefined" && !isXML ) {
 				var m = context.getElementById(match[1]);
-				return m ? m.id === match[1] || m.getAttributeNode && m.getAttributeNode("id").nodeValue === match[1] ? [m] : undefined : [];
+				return m ? m.id === match[1] || typeof m.getAttributeNode !== "undefined" && m.getAttributeNode("id").nodeValue === match[1] ? [m] : undefined : [];
 			}
 		};
 
 		Expr.filter.ID = function(elem, match){
-			var node = elem.getAttributeNode && elem.getAttributeNode("id");
+			var node = typeof elem.getAttributeNode !== "undefined" && elem.getAttributeNode("id");
 			return elem.nodeType === 1 && node && node.nodeValue === match;
 		};
 	}