[brndagnall@gmail.com]

Thanks Mike.   

I believe  I have sidestepped the problem.   In Settings, I have ticked ALWAYS SHOW THE TITLE BAR. 

So now, i select Annotation Editor from the title bar, and when finished annotating I am returned to the same title bar.  I press the Return arrow top left, and it returns me to the Library apparently  EVERY time.  

As indicated before, using the Android Back arrow did not always return to Library.

Sorry to have been troublesome.  But now everything is working just great for me.

Cheers

Brian D