Will a separate listening thread make a WinForm miss a change event?

Hello,

I am seeing some strange behavior in my application and I'm wondering if I spawn a separate listening thread to update my data source, is my form missing the change event because they are on seprate threads?  Sometimes the form displays the data update, sometimes it does not and there is no exception to examine.  I am not so familiar with multitheaded applications, but my code is a combination of code examples I've found for the repository and the socket, so I'm not sure I haven't mixed ideas in a way that doesn't put the update and the change event on separate threads.  Basically, my display form has a singleton DataSet as its datasource and my ServerTerminal class spawns a new thread to listen for incoming messages.  Handlers are called that populate the DataSet.  Again, I'm wondering if the change event that drives the form content is fired on a different thread than the repository update is taking place on.  I'd appreciate any help from a multithreaded app veteran.  

Here is the how the Dataset is defined:

using System;
using System.Data;
using System.Collections.Generic;
using GanttChart.DataAccess;

namespace GanttChart.Model
{
   public class WorkRepository
   {
      private ServerTerminal serverTerminal;
      private DataSet WorkRepo;
      private DataTable theVendors;
      private DataTable theTasks;

      private static readonly WorkRepository instance;
      public static WorkRepository Instance
      {
         get { return instance; }
      }
      static WorkRepository()
      {
         instance = new WorkRepository();
      }

      private WorkRepository()
      {
         InitializeRepos();
         serverTerminal = new ServerTerminal();
         serverTerminal.StartListen(2535);
      }
      public void InitializeRepos()
      {
         WorkRepo = new DataSet();

         theVendors = WorkRepo.Tables.Add("Works");
         theVendors.Columns.Add("VendorGuid");
         theVendors.Columns.Add("VendorID");
         theVendors.Columns.Add("VendorName");
         theVendors.Columns.Add("WorkStartTime", typeof(DateTime));
         
         DataColumn[] keys = new DataColumn[1];
         keys[0] = theVendors.Columns["VendorID"];
         theVendors.PrimaryKey = keys;

         theTasks = WorkRepo.Tables.Add("Tasks");
         theTasks.Columns.Add("TaskGuid");
         theTasks.Columns.Add("VendorID");
         theTasks.Columns.Add("TaskName");
         theTasks.Columns.Add("TaskStartTime", typeof(DateTime));
         theTasks.Columns.Add("TaskDuration", typeof(TimeSpan));
         theTasks.Columns.Add("ParentTaskGuid");
         theTasks.Columns.Add("TaskPercentComplete");
         theTasks.Columns.Add("AllProperties", typeof(Byte[]));

         DataColumn[] tasksKey = new DataColumn[1];
         tasksKey[0] = theTasks.Columns["TaskGuid"];
         theTasks.PrimaryKey = tasksKey;

         System.Data.DataRelation relOrdDet;
         System.Data.DataColumn colMaster;
         System.Data.DataColumn colDetail;
         colMaster = WorkRepo.Tables["Works"].Columns["VendorID"];
         colDetail = WorkRepo.Tables["Tasks"].Columns["VendorID"];
         relOrdDet = new System.Data.DataRelation("RelOrdDet", colMaster, colDetail);
         WorkRepo.Relations.Add(relOrdDet);
      }

      public Guid UpdateWork(WorkData Work)
      {
         Guid id;
         DataRow row = theVendors.Rows.Find(Work.vehId);
         if (row == null)
         {
            // need to insert row
            id = new Guid();
            theVendors.Rows.Add(new Object[] { id, Work.vehId, Work.name, Work.startTime });
         }
         else
         {
            // need to update row
            string idstring = row["VendorGuid"].ToString();
            id = new Guid(idstring);
         }
         return id;
      }

      public void UpdateTask(TaskData task)
      {
         DataRow row = theTasks.Rows.Find(task.parentGuid);
         if (row == null)
         {
            // need to insert row
            Guid id = new Guid(task.parentGuid);
            theTasks.Rows.Add(new Object[] { id, task.VendorID, task.VendorName, DateTime.Now, TimeSpan.FromMinutes(20), null, null });
         }
         else
         {
            // need to update row
         }

         // Add task as a child of the Vendor summary task
         theTasks.Rows.Add(new Object[] { Guid.NewGuid(), task.VendorID, task.name, DateTime.Now, task.duration, new Guid(task.parentGuid), task.taskPercentageComplete });
      }

      public DataSet GetWorkRepository()
      {
         return WorkRepo;
      }

      public string GetVendorCompanyName(string key)
      {
         string CompanyName;
         DataRow row = theVendors.Rows.Find(key);
         if (row != null)
         {
            CompanyName = row.Field<string>("VendorName");
            return CompanyName;
         }
         else
         {
            CompanyName = null;
         }
         return CompanyName;
      }
   }

  public class WorkData
   {
      public Guid VendorGuid;
      public string name;
      public DateTime startTime;
      public string vehId;
   }

   public class TaskData
   {
      public string taskGuid;
      public string VendorID;
      public string name;
      public string VendorName;
      public DateTime taskStart;
      public TimeSpan duration;
      public string parentGuid;
      public string taskPercentageComplete;
   }
}

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and here is how the socket code and handlers are defined:  

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading; 
using System.Windows.Forms;
using System.Runtime.Remoting.Messaging;
using System.Collections.Generic;
using GanttChart.Model;

namespace GanttChart.DataAccess
{
   public class ServerTerminal
   {
    private delegate void ProcessMsgDelegate(byte[] dgram);

    private Thread _listenThread;
    private UdpClient _client;

    
    private CoreMsgProcessor _processor = new CoreMsgProcessor("Listener", true);

    public void StartListen(int listenPort)
    {
      _processor.VendorIdMsgReceived += OnVendorIdentificationMsgReceived;
      _processor.PayloadDeliveryLocationMsgReceived += OnPayloadDeliveryLocationMsgReceived;
      _processor.InvalidMsgReceived += OnInvalidMsgReceived;
      _client = new UdpClient(listenPort);
      _listenThread = new Thread(new ThreadStart(Listen));
      _listenThread.Name = "Listen Thread";
      _listenThread.Start();
    }

    private void Listen()
    { 
      IPEndPoint ep = new IPEndPoint(IPAddress.Any, 0);
      
      ProcessMsgDelegate del = new ProcessMsgDelegate(_processor.ProcessMsg);
      AsyncCallback callback = new AsyncCallback(ProcessMsgCallback);

      for (; ; )
      {
        byte[] dgram = _client.Receive(ref ep);

        // This info can be useful if you care who sent the datagram.
        System.Diagnostics.Debug.WriteLine("Message Received");
        string a = ep.Port.ToString();
        System.Diagnostics.Debug.WriteLine(ep.Address.ToString() + ":" + ep.Port.ToString() + "\n");

        IAsyncResult ar = del.BeginInvoke(dgram, callback, null);
      }
    }

    private void ProcessMsgCallback(IAsyncResult ar)
    {
       AsyncResult result = (AsyncResult)ar;
       ProcessMsgDelegate del = (ProcessMsgDelegate)(result.AsyncDelegate);
       del.EndInvoke(ar);
    }


    private void OnInvalidMsgReceived(object sender, InvalidMsgEventArgs e)
    {
        System.Diagnostics.Debug.WriteLine("Invalid received. Reason: " + e.Reason + ".\r\n");
    }

    private void OnVendorIdentificationMsgReceived(object sender, VendorIdMsgReceivedEventArgs e)
    {
       WorkData Data = new WorkData();
       Data.VendorGuid = new Guid();
       Data.vehId = e.Message.VendorId.ToString();
       Data.name = e.Message.AtcCompanyName;
       WorkRepository.Instance.UpdateWork(Data);
    }

    private void OnPayloadDeliveryLocationMsgReceived(object sender, PayloadDeliveryLocationMsgReceivedEventArgs e)
    {
        WorkData Data = new WorkData();
        Data.vehId = e.Message.VendorId.ToString();
        Data.name = LookupVendorName(e.Message.VendorId);
        if (Data.name == null)
           Data.name = "VendorID = " + e.Message.VendorId;
        Data.startTime = ConvertDateTime(e.Message.TimeStamp);
        Guid id = WorkRepository.Instance.UpdateWork(Data);

        double lat = e.Message.GPSLatitude * 57.295779513082320876798154814105;
        double lon = e.Message.GPSLongitude * 57.295779513082320876798154814105;

        TaskData Task = new TaskData();
        Task.taskGuid = e.Message.MsgInstanceId.ToString();
        Task.VendorID = e.Message.VendorId.ToString();
        Task.taskStart = Data.startTime;
        TimeSpan a = new TimeSpan(Data.startTime.Hour, Data.startTime.Minute, Data.startTime.Second);
        Task.name = "Stare at (Lat,Lon):  " + lat + " , " + lon;
        TimeSpan span = new TimeSpan(-1, -1, -1);
        Task.duration = span.Duration();
        Task.taskPercentageComplete = Convert.ToString(25);
        Task.parentGuid = id.ToString();
        Task.VendorName = Data.name;
  WorkRepository.Instance.UpdateTask(Task);                        System.Diagnostics.Debug.WriteLine("OnPayloadDeliveryLocationMsgReceived");
    }
   }
}

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Given this setup, is it possible that my form's change event is not firing?  If so, what can I do to fix it?  

Thanks in advance!
IWP