Unity plugin with native intefaces (java)

Dear Vuforia Support, We are developping a mobile application (IOs / Android) which uses both native interfaces (XCode / Java) and the Unity QCAR Plugin (with Unity 4.1.2). In this application, we need to switch between the native and the Unity views (i.e. navigating from one to the other). It works perfectly on IOs. But, for Android, as long as we go back to the native views (from Unity view), the application closes itself after about 2s.Note that we have to inherit from  QCARPlayerActivity class for generating this application. When trying to do the same thing with a standard Unity project (without QCAR and thus inheriting from UnityPlayerActivity), we do not have any problem. The last point is that we found a way to get around the issue : it consists in destroying the Unity activity when going back to native interface (in the OnPause() callback of the QCARPlayerActivity class). Unfortunately, that forces Unity to initialize again each time we go back in the Unity view, which could be quite long depending on the Unity project. We can provide you unitary tests we made (.apk and Eclipse project). Thank you for your support, Christophe Montandon - Diotasoft.