双重刷新后，Ajax调用PHP脚本返回状态0

I had a simple form that used JQuery AJAX to call a PHP script and perform some work. This code worked properly for 2+ years and then all the sudden stopped working - and has some weird behavior I've having trouble debugging.

Here's the HTML code:

  <div class="form-group">
    <label for="commenter-name" class="col-sm-3">Name</label>
    <div class="col-sm-9">
      <input type="text" class="form-control" name="commenter-name" id="commenter-name" placeholder="Enter Name" value="" >
    </div>
  </div>
  <div class="form-group">
    <label for="commenter-comment" class="col-sm-3">Comment</label>
    <div class="col-sm-9">
      <textarea class="form-control" rows="3" name="commenter-comment" id="commenter-comment" placeholder="Enter Comment"></textarea>
    </div>
  </div>
  <div class="clear"></div>
  <div class="form-group custom-form">
    <div class="col-sm-3"></div>
    <div class="col-sm-9">
      <input id="submit-comment" type="button" class="btn btn-success" value="Submit">
    </div>
  </div>

Here's the JS code (using JQuery 1.8.3):

$("#submit-comment").click(function(event) {
      $.ajax({
        type: "POST",
          url: "_code/ProcessPoll.php",
          data: { comment : comment,  name : name, commenter_position : commenter_position }
      })
});

Here's the PHP code:

if ($_POST["comment"])
{
        //log results of the poll
        $log = new PollsLogging($_POST["name"], $_POST["comment"], "comment", "comment", $_POST["commenter_position"]);
        $log->WriteToFile();
}

This code worked effectively for 2+ years and now this is the behavior:

1. Enter info in the textbox fields and hit the submit button
2. The click event is triggered and then the JQuery AJAX call is made, but does not bring back a completion, success, or failure (I'm using the debugger in Chrome)
3. Then I refresh the page and I am getting a status of 0 in the error from the AJAX (I don't have the debugging in here, but I just used this to figure it out: error: function(jqXHR, textStatus, errorThrown) {alert(jqXHR.status)}

Could something have changed in the different versions of all the major browsers for this to stop working? Am I blatantly missing something? I read a few things about the AJAX call might never be completing, but I'm not sure how to handle that... especially since I haven't made any code changes to this... I also have a few other small programs that are similar and those have also stopped working and are behaving in a similar way!

Any help/guidance is appreciated.

I'm sorry I can't comment because of my poor reputation, so I post this as an answer.

Actually, it's not possible to provide you an answer, we lack informations. I don't see any problem in the code you presented.

You're talking about a strange behaviour, can you describe it ? Did you tried to use a tool like Firebug to monitor your request headers ?