jQuery Grid Plugin - jqGrid

I have a jqgrid with a navGrid plugin that is configured to show 10 records at a time, and a server side query that has 42 rows.

When the page first loads, the server generates JSON to show that this is page 1 of 5, 42 records total, and gives the 10 records; These display no problem.

When I use the pagination buttons, these generate an AJAX call to the server asking for the appropriate page. The response contains a new set of 10 records (or 2 for the last page.).

My problem is that the jqGrid doesn't refresh after getting the server response – it continues to show the data that was originally loaded  (page 1). Also, while the buttons are active appropriately (I can click next until I hit the last page and each one generates an AJAX call), the button display doesn't change – the previous button is always shown disabled, for example. (but it works, and generate the appropriate AJAX call.)

Here's some code that shows the issue:

$("#filingGrid").jqGrid({
url: CCF.docroot + "cfcs/grid/filings.cfc?method=getFilingsByEntity&le_id=31902&returnFormat=plain",
  datatype: "json",
  colNames:['Status', 'Filing ID','Frequency', 'Year', 'Period Start','Period End', 'Due Date', 'Filed'],
  colModel:[
    {name:'status', index:'status', formatter: statusFormatter, align: "center" },
    {name:'id', index:'id', classes: "faux-link" },
    {name:'period_description', index:'period_description'},
    {name:'period_year', index:'period_year', width:75},
    {name:'period_start_date', index:'period_start_date', formatter: dateFormatter},
    {name:'period_end_date', index:'period_end_date', formatter: dateFormatter},
    {name:'external_due', index:'external_due', formatter: dateFormatter},
    {name:'external_file', index:'external_file', formatter: dateFormatter}
],
  rowNum: 10,
  pager: "#filingGridPager",
  viewrecords: true
}).jqGrid('navGrid','#filingGridPager', {});

The HTML this is working on is: <div id="filingGridPager"></div><table id="filingGrid"><tr><td></td></tr></table>. I verified I'm loading the locale JS and then the full jqGrid JS (selecting all the various options from the 3.8 download).

Any help is greatly appreciated, thanks.