SignalR - Jquery response - 304 error

[miss786]

Dear all, I am running the following script on the client-side and the script is failing to update, when there is change in the database. I debugged the script using web-browser debugger and discovered my Jquery scripts are responding back as "304 not modified". I am assuming the server code is sending 304 resp. if so, what tests can I carry out, to help me debug server code, to find where the logic maybe going wrong. Client-side:

<script src="../Scripts/jquery-1.6.4.js"></script>
<script src="../Scripts/jquery.signalR-2.1.2.min.js"></script>
<script src='<%: ResolveClientUrl("~/signalr/hubs") %>'></script>
<script type="text/javascript">
$(function () {
// Declare a proxy to reference the hub.
var notifications = $.connection.NotificationHub;
// Create a function that the hub can call to broadcast messages.
notifications.client.recieveNotification = function (role, descrip) {
// Add the message to the page.
$('#spanNewMessages').text(role);
$('#spanNewCircles').text(descrip);
};
// Start the connection.
$.connection.hub.start().done(function () {
notifications.server.sendNotifications();
alert("Notifications have been sent.");

}).fail(function (e) {
    alert(e);
});
//$.connection.hub.start();

});
</script>

New Notifications

New = role.
New = descrip.

The server side code is created signalR hub class and also has sql dependency logic as well:

[HubName("NotificationHub")]
public class notificationHub : Hub
{
string role = "";
string descrip = "";

\[HubMethodName("sendNotifications")\]
public void SendNotifications()
{
    using (var connection = new SqlConnection(ConfigurationManager.ConnectionStrings\["##########"\].ConnectionString))
    {

        string query = "SELECT top 1 \[role\],\[description\] FROM \[dbo\].\[User\] order by uploadDate desc";
        connection.Open();
        SqlDependency.Start(GetConnectionString());

        using (SqlCommand command = new SqlCommand(query, connection))
        {

            try
            {
                command.Notification = null;
                DataTable dt = new DataTable();
                SqlDepe