Ext.override(Ext.form.ComboBox, {
	initList: (function(){
		if(!this.tpl) {
			this.tpl = new Ext.XTemplate('<tpl for="."><div class="x-combo-list-item">{',  this.displayField , ':this.blank}</div></tpl>', {
				blank: function(value){
					return value==='' ? '&nbsp;' : value;
				}
			});
		}
	}).createSequence(Ext.form.ComboBox.prototype.initList)
});

//Stack overflow in IE6/7 using prototype 1.6.1_rc3
/*
(function(){
	   //should be Ext's implem at this point
	   var eDefer = Function.prototype.defer; 

	   Function.prototype.defer = function() {
	    var args = arguments, L = args.length;
	    if( L==0 || ( L==1 && args[0]==1)) //common for Prototype Ajax requests
	    {
	        return this.delay.curry(0.01).apply(this, args);
	    }
	    return eDefer.apply(this, args);
	  }; 
})();
*/