jQuery Grid Plugin - jqGrid

I've been messing with this for a few days now and I'm losing my mind. I was able to get jqGrid working, using a 'local' datatype and now I'm trying to tie it to my SQL data. I get no errors, just a blank grid. I've searched the web and tried numerous examples with no luck. The grid displays and the column headers appear, just no data. I also receive no js errors. I'm not interested in paging, sorting, searching, etc... at this point. Just need to get the data displaying. Can someone point me in the right direction?

VB.NET code:
============
Public Function GetGridData() As JqGridData
    Dim sql As String = "Select unit_number, product_code, blood_type, 'No Match' scan_result From product_header Where (product_id < 20) Order By 1, 2, 3"

    Dim dt As New DataTable()
    Dim conn As New SqlConnection(ConfigurationManager.ConnectionStrings("conn").ConnectionString)
    Dim adapter As New SqlDataAdapter(sql, conn)
    adapter.Fill(dt)

    Dim result As New JqGridData()
    Dim gridRows As New List(Of TableRow)()
    Dim idx As Integer = 1

    For Each row As DataRow In dt.Rows
        Dim newrow As New TableRow()
        newrow.id = idx
        newrow.cell = New List(Of String)(4)
        newrow.cell(0) = row(0).ToString()
        newrow.cell(1) = row(1).ToString()
        newrow.cell(2) = row(2).ToString()
        newrow.cell(3) = row(3).ToString()
        gridRows.Add(newrow)
    Next

    result.total = 2
    result.page = 1
    result.records = gridRows.Count
    result.rows = gridRows

    Return result
End Function

Public Class TableRow

    Private m_id As Integer
    Private m_cell As List(Of String)

    Public Property id() As Integer
        Get
            Return m_id
        End Get
        Set(ByVal value As Integer)
            m_id = value
        End Set
    End Property

    Public Property cell() As List(Of String)
        Get
            Return m_cell
        End Get
        Set(ByVal value As List(Of String))
            m_cell = value
        End Set
    End Property

End Class

Public Class JqGridData

    Private m_total As Integer
    Private m_page As Integer
    Private m_records As Integer
    Private m_rows As List(Of TableRow)

    Public Property total() As Integer
        Get
            Return m_total
        End Get
        Set(ByVal value As Integer)
            m_total = value
        End Set
    End Property

    Public Property page() As Integer
        Get
            Return m_page
        End Get
        Set(ByVal value As Integer)
            m_page = value
        End Set
    End Property

    Public Property records() As Integer
        Get
            Return m_records
        End Get
        Set(ByVal value As Integer)
            m_records = value
        End Set
    End Property

    Public Property rows() As List(Of TableRow)
        Get
            Return m_rows
        End Get
        Set(ByVal value As List(Of TableRow))
            m_rows = value
        End Set
    End Property

End Class

js code:
========
$(document).ready(function(){
    $("#list").jqGrid({
        url: 'Display.aspx/GetGridData',
        datatype: 'json',
        mtype: "GET",
        ajaxGridOptions: { contentType: 'application/json; charset=utf-8' },
        serializeGridData: function (data) {
            return JSON.stringify(data);
        },
        jsonReader: {
            root: "rows",
            page: "page",
            total: "total",
            records: "records",
            repeatitems: true
        },
        colModel: [
            {name: 'unit_number', label: 'Unit Number', width: 100, align: 'center'},
            {name: 'product_code', label: 'Product Code', width: 200, align: 'center'},
            {name: 'blood_type', label: 'Blood Type', width: 200, align: 'center'},
            {name: 'scan_result', label: 'Scan Result', width: 200, align: 'center'}
        ],
        rowNum: 10,
        rowList: [10, 20, 30],
        sortname: 'id',
        sortorder: "asc",
        pager: "#pager",
        viewrecords: true,
        caption:  'My first grid'
    }).jqGrid('navGrid', '#pager', {edit: false, add: false, del: false, search: true});
});