供应商标识符在iOS 5.0版中不起作用

I'm using the Vendor Identifier since use of UDID is deprecated, but after using this App does not work in the devices with iOS version less than 6.0. Can anyone tell me what needs to be done ? Will the app only be supported in iOS 6.0 and above ? How do I make my app function in devices with iOS version less than 6.0 ? Below is the code i'm using :I'm using the Vendor Identifier since use of UD