Using delegate with threads

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C#

C#4.0

I have an application which uses a number ot timer threads. These threads use a delegate to call functions on the main thread, and work fine. I am implementing a new thread (not a timer) and am having issues with the delegate, code below.

//This is the decleration at the begining of the main thread used by timers and new thread
//delegate so worker threads can call local functions

        public delegate void DoSomething();


// this is part of the new thread code where the delegate is being called

                  if (this.InvokeRequired)
                    {
                        try
                        {

                            DoSomething d = new DoSomething(LoadChange);
                            this.Invoke(d);
                        }
                        catch (ObjectDisposedException r)
                        {
                            MessageBox.Show("caught Object Dispose {0}", r.ToString());
                        }
                        catch (NullReferenceException r)
                        {
                            MessageBox.Show("caught null ref {0}", r.ToString());
                        }
                        catch (IndexOutOfRangeException r)
                        {
                            MessageBox.Show("caught ind out of range {0}", r.ToString());
                        }
                    }
                    else
                        this.LoadChange();
                   
                    Thread.Sleep(frq);

                }
            }
            
            catch (Exception ex)
            {
                MessageBox.Show("Error in repeat send routine." + ex);
            }
            START.BackColor = Color.LightSkyBlue;
        
        }

//this is function in the main thread to be called by the delegate

        private void LoadChange()
        {
            string current = repeat;
            if (!current.Equals(repeat))
            {
                Message2.Text += repeat;
                current = repeat;
            }
            
        }

I do not have a lot of experience with delegates and threads. The timer threads are exactly like the code in the new thread(cut and paste) except the new thread is calling a different function. When I compile and run the new thread I get no errors but the LoadChange function never gets called, at least the break point in the LoadChange function never gets hit. Any help would be appreciated.
Dave