What I noticed seemed to work for me last night was to delete any files from my project and the Finder folder for the same project that are sitting next to the main project file. I also had different names for the older and newer, so I deleted the older ones from the plist file under both the icons and the iOS 5 icons. Finally, I made the + Shift + K command to clear the project. All this seemed to do it for me on the emulator and on my iPhone, I just had to reboot.