Time for some website programming: Amazon was notifying me that Amazon 'Product Advertising API' requests (formerly known as Amazon Web Service) now need to be digitally signed. The 'why' of this is probably something with security. For the 'how' I had to revive those braincells which once programmed Amazon Web Service into The Virtual Bookcase. Those braincells took time as I was first browsing in the wrong sourcefiles. But, after having a peek at Jaap's free Amazon PHP Scripts and incorporating the change to sign requests into my sources, I found the right way again.
One of those times I am glad I have a development version of the site (smaller database, code in development), a qa version (production database, candidate code) and a running version (production database, production code) to test changes like this. The visitors of The Virtual Bookcase never saw all the tries in getting the code to work right.It was a while since I did any serious work on that site. Otherwise it runs on autopilot and I only add new books and reviews from time to time. Ok, the income from the site has dropped in the same way.