<p>I have determined that my JSON, coming from the server, is valid (making the ajax call manually), but I would really like to use JQuery. I have also determined that the "post" URL, being sent to the server, is correct, using firebug. However, the error callback is still being triggered (parse error). I also tried datatype: text.</p>

<p>Are there other options that I should include?</p>

<pre><code>$(function() {
    $("#submit").bind("click", function() {
        $.ajax({
            type: "post",
            url: "http://myServer/cgi-bin/broker" ,
            datatype: "json",
            data: {'start' : start,'end' : end},
            error: function(request,error){
                alert(error);
            },
            success: function(request) {
                alert(request.length);
            }
        }); // End ajax
    }); // End bind
}); // End eventlistener
</code></pre>

Here are a few suggestions I would try:
1) the 'datatype' option you have specified should be 'dataType' (case-sensitive I believe)
2) try using the 'contentType' option as so:
```
```
contentType: "application/json; charset=utf-8"
```
```
I'm not sure how much that will help as it's used in the request to your post url, not in the response.
See this article for more info:
http://encosia.com/2008/06/05/3-mistakes-to-avoid-when-using-jquery-with-aspnet-ajax
(It's written for asp.net, but may be applicable)
3) Triple check the output of your post url and run the output through a JSON validator just to be absolutely sure it's valid and can be parsed into a JSON object.
http://www.jsonlint.com
Hope some of this helps!