To be honest the problem is so minor I don't really think it's worth it playing around with files to fix it if you don't think it's something relevant to development. It's a minor nitpick, I'm loving the feeling my Kindle gets when I see the cover of the book I'm reading, it's great work!
I do have one different issue, though: I just but "The Name of the Wind" on the Amazon Kindle store (
http://www.amazon.com/gp/product/B00...=docs-os-doi_0) and the hack is using the title page as the screensaver instead of the cover... since this is an official .azw3 file from Amazon I can't really edit it in Calibre to change the "cover". Is there something we can do with these cases?