+1  A: 

It could be a caching issue. Try setting the cache option to false, and/or using a cache breaker (which is a random number, or timestamp, passed along with the URL):

$('.nextQuestion').live('click', function(e){
    $.ajax({
        type:'GET',
        cache: false,
        url:'/includes/quiz.php?' + Math.round(new Date().getTime() / 1000),
        success:function(data){
            $('#game_response').replaceWith(data);
        }
    });
    return false;
});

You could also try using a POST request instead.

karim79
cache will append a timestamp and keep IE from caching the request
Bob Fincheimer
Yes it will (I just read it myself). I think I'll leave the timestamp thing there anyway, though.
karim79
You learn something new every day. Thanks very much for your quick response. I added cache: false, and problem solved.
wesada
@wesada - you are most welcome. Glad that solved your problem!
karim79