That seems to have done it, thank you. I hadn't realized that my SS was that far out-of-date - it was working so well!
I've now seen my Kindle restart two times in a row, which I hadn't seen before, so I'm ready to pronounce my problem 'fixed'.
Thanks, and I'm sorry I missed something so simple as out-of-date software. I'll try to keep up next time
Tracey