Yes, that is very annoying. It should just send you back to the page you were already on and to the position on the page where the comment you clicked is.
You could probably also do some clever trick with checkboxes, the css3 :checked pseudo class, and background images to make it work without javascript and without page refreshes. Browser support isn't going to be great atm though.
I would expect that it can be reasonably easy fix (a few lines on the right places) to simply deliver some sane content as the result of the vote HTML query.
Shouldn't the referrer tag from the query be enough?
