Custom isResumed method crashes application at start with java.lang.LinkageError exception

I have found an interesting case producing the java.lang.LinkageError exception.

In my base activity there is an isResumed field, I set it to true in onResume - and to false in onPause.
It's protected field.

Today I decided to add a method to get that value from a fragment, so I have added isResumed() method

public class BaseActoinBarActivity extends ActionBarActivity {

    protected boolean isResumed;

    @Override
    protected void onResume() {
        super.onResume();
        isResumed = true;
        ...
    }

    ...

    public boolean isResumed() {
        return isResumed;
    }
    
    ...
}

public class StartActivity extends BaseActionBarActivity {
...
}

Ok, after I have started my application I have got an exception:

05-07 18:45:21.020  14466-14466/? I/art﹕ Rejecting re-init on previously-failed class java.lang.Class<ru.xxxxxx.ui.base.BaseActionBarActivity>
05-07 18:45:21.020  14466-14466/? I/art﹕ Rejecting re-init on previously-failed class java.lang.Class<ru.xxxxxx.ui.base.BaseActionBarActivity>
05-07 18:45:21.020  14466-14466/? I/art﹕ Rejecting re-init on previously-failed class java.lang.Class<ru.xxxxxx.ui.StartActivity>
05-07 18:45:21.021  14466-14466/? I/art﹕ Rejecting re-init on previously-failed class java.lang.Class<ru.xxxxxx.ui.StartActivity>
05-07 18:45:21.021  14466-14466/? D/AndroidRuntime﹕ Shutting down VM
05-07 18:45:21.274  14466-14466/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: ru.xxxxxx.ui, PID: 14466
    java.lang.LinkageError: ru.simpls.mtsbank2.ui.StartActivity
            at dalvik.system.DexFile.defineClassNative(Native Method)
            at dalvik.system.DexFile.defineClass(DexFile.java:226)
            at dalvik.system.DexFile.loadClassBinaryName(DexFile.java:219)
            at dalvik.system.DexPathList.findClass(DexPathList.java:321)
            at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:54)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
            at ru.simpls.mtsbank2.ui.SplashScreen$1.handleMessage(SplashScreen.java:42)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5254)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

It's really funny :)

(SplashScreen is a splash screen activity, it starts StartActivity)