When looking at the +/- scores for a post, it gets automatically closed when the score live updates.
Normally I guess this wouldn't be too big of a problem, but for questions such as this and answers like this (admittedly where we were playing with making the numbers spin) I'm pretty sure I got RSI from clicking the same place so often just for it to stay open long enough to be meaningful.
Don't know if this is a bug or just a limitation of the live-refresh system (please delete tags as appropriate) but it really was quite irritating!
N.b. because of the ... unusual... voting that was happening on Jeff's answer, I'm assuming that it was just closing the box on a new vote. It could have actually been when votes were undone (un-downvote in particular), however, I can't be sure.
^^Having just painstakingly watched the net vote counts on this question, it's definitely on all votes.
Could the live refresh be tweaked to cope with showing net upvote/downvote scores on a post as they come in rather than closing the box to see the total score again?