Unable to upvote or downvote threads

I'm having this issue right now, and I came to this section to see if others were having the problem.

I was able to vote on threads and posts a few minutes ago (ignoring the occasional "so sad, you are not authorized" message), but now when I click on an arrow, I get no response at all. I've tried relogging, and it doesn't help.

I've tested this in Firefox and Chrome, so it doesn't seem to be a browser-specific issue.

Edit: Came back an hour later with nothing else changed, and it's suddenly working again. I suspect server-side problems.