SurfaceView is distorted after switching back to App

If i switch back from the home menu to my App sometimes the SurfaceView gets distorted like this:

http://ift.tt/1vnNMhM

The xml layout of the surfaceview looks like this:

> <com.example.standardbenutzer.adelpath.DrawingView
>     android:id="@+id/surface"
>     android:layout_width="fill_parent"
>     android:layout_height="fill_parent"
>     android:layout_centerInParent="true"/>

Any solutions how i can fix this distortion?

Merry christmas :)