There's a strange thing going on with my reputation history. On June 30th, I supposedly voted down an answer. I can't remember if I did; it links to this answer and in any case I'm able to downvote it again.
This record does not show up at all in my 'reputation log' (https://ell.stackexchange.com/reputation). Is this some weird caching issue, or is there anything wrong on a deeper level?