Thanks guys,
The BAL file has always been present and I just can't understand why there's a 'FileNotFound' exception.
Tried the '#DebuggerForceStandardAssets: True' and that got over the error (in debug mode). However, the debug installed widget didn't respond to touch. So I've abandoned Debug Mode.
Now compiled in release mode and it works. Thanks Erel.
Time to get back to the issue with the app.: tracking down the instability. Lack of response to touch inputs after hibernation, over time. I reckon it is something to do with the OS interfering with the service, in some way.
Thanks again.