You are approximately 50 versions behind. Update calibre and see if you still have the problem.
(In case you are wondering why you are 50 versions behind, calibre is released weekly, linux distros are for the most part released once. Naturally, they are out of date almost as soon as they are released. Rolling-release distros like Arch Linux or Gentoo don't have those flaws. Update from the standalone binary package at
http://calibre-ebook.com/download_linux. See my sticky thread for auto-updating
HERE.)