I ordered a standard penabled Wacom stylus from Amazon (this one:
http://www.amazon.com/gp/product/B00...00_i00_details) and I can verify that it doesn't work - you can occasionally get a response if you lay it on its side on the screen and slide it around, but it's not at all useful. Time to test Amazon's fabled return policies...
However, Tatiana Zagorovski at ereaders-plus.com kindly put me in touch with the Pocketbook USA service people (Bill,
service@pocketbook-usa.com) and they're sending me a proper replacement for $15 and a few bucks shipping.