Aha! That's worked. I set minimum articles to 1 & it successfully pulled them down, created the ebook & marked as read with no exceptions.
Sorry if I threw you a red herring, guess I should have picked that up from the code
I think it's right that no ebook is generated if there are not enough articles, but don't know if there's a way of doing that without throwing an exception though.
I was going to debug through it myself, but only got as far as setting up Eclipse & PyDev & no as far as finding how to import the calibre libraries into a stand alone project. (I'm usually a C#/Java fella)