Fix for defect on locking and unlocking device, app would freeze or crash. Problem was assumption that surface would always be destroyed in tandem with appplication teardown, which is the case when putting app into background without locking but surface is *not* destroyed when locking and unlocking. Fix is to keep member reference to SurfaceHolder, and kill the native connection to the surface when the app is paused and reconnect when app is resumed - the holder reference is invalidated on surface destroy. Buddy = Tim J.