如何从UITabBar控制器中的控制器使用UISearchDisplayController？

I have an UITabBar controller managing several controllers (using SDK 3.0). One of these is a tableView controller and I need to provide a search capability using the UISearchDisplayController. All of my code is based on Apple TableSearch example. However, when clicking on the tab, the tableView controller appears showing its related content, but no searchBar appears. I have checked the xib in IB to make sure that all of the outlets are properly set, but no matter what I try self.searchDisplayController is always nil and the search bar does not appear.I have an UITabBar controller managing several