This is known as 'Murphy's (forum-)law:

I search for hours, and at my wit's end place a question in a forum, and then within 10 or 15 minutes I find my own answer....

i.o.w. I have found the solution, just click on one of the humongous, nót to be overlooked, buttons in the taksbar (the one with the Calibre-logo) and presto, problem solved!!
Thanks for reading this most embarassing of introductions