When I install HotPot on a clean Moodle 2.2.1 install, I see the following when I go to the Import section of the Question Bank:
I followed the installation instructions correctly: copied mod/hotpot to moodle/mod/hotpot, and copied question/format/hotpot to moodle/question/format/hotpot. I'm using the en_us language. I also purged all of the caches in the Moodle admin area.
Any idea why it isn't reading the hotpot language file?