Are you using MVC?

[EDIT]

I'm using .Net MVC 3 and loading a datagrid via JSON.

The HTML:

Code:

    ....
    <script src="../../Scripts/jquery-1.7.2.min.js" type="text/javascript"></script>
    <script src="../../Scripts/jquery.easyui.min.js" type="text/javascript"></script>
    <script src="../../Scripts/jquery-ui-1.8.22.custom.min.js" type="text/javascript"></script>
    <script src="../../Scripts/jquery.blockUI.js" type="text/javascript"></script>
    <link href="../../Content/jquery-ui-1.8.22.custom.css" rel="stylesheet" type="text/css" />
    <link href="../../Content/Site.css" rel="stylesheet" type="text/css" />
    <link href="../../Content/themes/icon.css" rel="stylesheet" type="text/css" />
    <link href="../../Content/themes/default/tree.css" rel="stylesheet" type="text/css" />
    <link href="../../Content/themes/default/datagrid.css" rel="stylesheet" type="text/css" />
    ...
    <table id="ListItemsGrid"></table>
    ...

The Javascript to instantiate the Datagrid:

Code:

jQuery("#ListItemsGrid").datagrid({
   title: "Inventory List",
   url: "/Categories/GetJSONItemsList",
   queryParams: { ID: '1' }, // This is hard-coded
   pagination: true,
   width: 600,
   height: 300,
   columns: 
                        [[
                            {   field: 'ID',
                                title: 'ID',
                                sortable: true,
                                width: 65 
                            },
                            {   field: 'Name',
                                title: 'Name',
                                sortable: true,
                                width: 400 
                            },
                            {   field: 'Location',
                                title: 'Location',
                                sortable: true,
                                width: 100 
                            }
                        ]]
      });

The output of /Categories/GetJSONItemsList:

Code:

[
{"ID":1,"Name":"Canon Sureshot V098","Location":"Vernon"},
{"ID":2,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":3,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":4,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":5,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":6,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":7,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":8,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":9,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":10,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":11,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":12,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":13,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":14,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":15,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":16,"Name":"Canon Rebel X2i","Location":"Calgary"},
{"ID":17,"Name":"Canon Rebel X2i","Location":"Calgary"}
]

I've attached a screen capture of the resulting Datagrid (capture.png). If I click on the "next page" pagination button, all of the elements appear (all 17 on one page). I've included a screen shot of that too (capture2.png).

EDIT:
When I add the following code:

Code:

jQuery("#ListItemsGrid").datagrid({
...
 onLoadSuccess: function (data) {
    jQuery.each(data, function (index, o) {
       alert(o);
    })

I first get an alert that says "17" and then i get a second alert that says "[object: Object],[object: Object],[object: Object],[object: Object]......" 17 times.
However, when I just call /Categories/GetJSONItemsList I get the JSON array shown previously.

My MVC Controller is as follows:

Code:

        [HttpPost]
        public JsonResult GetJSONItemsList(int ID)
        {
            Category aCategory = new Category(ID);
            List<Item> itemsInCategory = aCategory.GetItemsInCategory();
            return this.Json(itemsInCategory, JsonRequestBehavior.AllowGet);
        }