Menu: Only look for .ui-menu-item elements to determine if a menu item is the first or last element in the menu. Fixes #5528 - Autocomplete: Issue when try to navigate using up key by keyboard in IE6.

Author: scottgonzalez

ui/jquery.ui.autocomplete.js

@@ -433,11 +433,11 @@ $.widget("ui.menu", {
 	},
 
 	first: function() {
-		return this.active && !this.active.prev().length;
+		return this.active && !this.active.prevAll(".ui-menu-item").length;
 	},
 
 	last: function() {
-		return this.active && !this.active.next().length;
+		return this.active && !this.active.nextAll(".ui-menu-item").length;
 	},
 
 	move: function(direction, edge, event) {