Unable to instantiate activity

Unable to instantiate activity ComponentInfo{com.tvie.ilook.pad/com.tvie.ilook.pad.RootActivity}: java.lang.ClassNotFoundException: Didn't find class "com.tvie.ilook.pad.RootActivity"on path: DexPathList[[zip file "/data/app/com.tvie.ilook.pad-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.tvie.ilook.pad-1,/vendor/lib,/system/lib]]

11-08 19:08:42.363: E/AndroidRuntime(7540): FATAL EXCEPTION: main
11-08 19:08:42.363: E/AndroidRuntime(7540): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.tvie.ilook.pad/com.tvie.ilook.pad.RootActivity}: java.lang.ClassNotFoundException: Didn't find class "com.tvie.ilook.pad.RootActivity" on path: DexPathList[[zip file "/data/app/com.tvie.ilook.pad-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.tvie.ilook.pad-1, /vendor/lib, /system/lib]]
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.os.Looper.loop(Looper.java:137)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.app.ActivityThread.main(ActivityThread.java:5103)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at java.lang.reflect.Method.invokeNative(Native Method)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at java.lang.reflect.Method.invoke(Method.java:525)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at dalvik.system.NativeStart.main(Native Method)
11-08 19:08:42.363: E/AndroidRuntime(7540): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.tvie.ilook.pad.RootActivity" on path: DexPathList[[zip file "/data/app/com.tvie.ilook.pad-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.tvie.ilook.pad-1, /vendor/lib, /system/lib]]
11-08 19:08:42.363: E/AndroidRuntime(7540):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
11-08 19:08:42.363: E/AndroidRuntime(7540):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128)
11-08 19:08:42.363: E/AndroidRuntime(7540):     ... 11 more