is there any reason why you are using animate over slideUp? with the animate, I would try using height instead of positioning. You also need to set a time for the move, otherwise it will move so fast that it will look like the hover. I am not an expert either, not sure this will work, but you could try something like this
"backgroundPosition" : "0px 30px"}, 5000);
add the time on there in miliseconds.