I don't know if i's your 'fault' or Amazon's, but the files I get through Amazon is named exactly the same (rekindleit-mobi.mobi), and if I want to download for example a handful of articles, I have to manually rename them one after one as I download them from the email. It's overall more work than creating custom-sized PDFs from the web pages. I've so far only tried articles from this site:
http://www.alistapart.com , but I don't get the images in the rekindleit file, and I would like to have them included.