my brothers ipod recently kept re-springing after using sbsettings successfully for quite some time now I knew it was sbsettings because i uninstalled it with cydia and he had no more problems weird right?
It might be a hiccup. Reinstall and try again. If that still doesn't work, he might have to restore to a fresh copy of iOS 5.1.1 with saved blobs and try it again. I've had cases where that was present on iPhones and iPod Touches