应用程序崩溃 - [__ NSCFSet bytes]：无法识别的选择器发送到实例“”？

I developing an application that application well worked for me my XCode version is 4.2.1 and iOS version is 5.0 ARC enable code. My process is i showing a bunch of YouTube videos in tableview using web service. I cache those video Icon in my directory. When i sending that application for apple review... application going crash there, the crash report is following,I developing an application that application we