Invaild Operation Exception error !..

Error Detalis :
 
System.InvalidOperationException was unhandled
  Message=Çapraz is parçacigi islemi geçerli degil: 'textBox1' denetimine olusturuldugu is parçacigi disinda baska bir is parçacigindan erisildi.
  Source=System.Windows.Forms
  StackTrace:
       konum: System.Windows.Forms.Control.get_Handle()
       konum: System.Windows.Forms.TextBoxBase.GetSelectionStartAndLength(Int32& start, Int32& length)
       konum: System.Windows.Forms.TextBoxBase.AppendText(String text)
       konum: WindowsFormsApplication4.Form1.Log(String pText) C:\Users\GrovellVision\Documents\Visual Studio 2010\Projects\WindowsFormsApplication4\WindowsFormsApplication4\Form1.cs içinde: satir 40
       konum: WindowsFormsApplication4.Form1.OnAdvise(Object sender, DdeAdviseEventArgs args) C:\Users\GrovellVision\Documents\Visual Studio 2010\Projects\WindowsFormsApplication4\WindowsFormsApplication4\Form1.cs içinde: satir 82
       konum: NDde.Client.DdeClient.OnAdviseReceived(Object sender, DdemlAdviseEventArgs internalArgs)
       konum: NDde.Foundation.Client.DdemlClient.AdviseLoop.Process(Int32 uType, Int32 uFmt, IntPtr hConv, IntPtr hsz1, IntPtr hsz2, IntPtr hData, IntPtr dwData1, IntPtr dwData2)
       konum: NDde.Foundation.Client.DdemlClient.ProcessCallback(DdemlTransaction transaction)
       konum: NDde.Foundation.Advanced.DdemlContext.OnDdeCallback(Int32 uType, Int32 uFmt, IntPtr hConv, IntPtr hsz1, IntPtr hsz2, IntPtr hData, IntPtr dwData1, IntPtr dwData2)
       konum: System.Windows.Forms.UnsafeNativeMethods.DispatchMessageA(MSG& msg)
       konum: System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
       konum: System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       konum: System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       konum: System.Windows.Forms.Application.Run(Form mainForm)
       konum: NDde.Advanced.DdeContext.DdeThread.Run()
       konum: System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       konum: System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       konum: System.Threading.ThreadHelper.ThreadStart()
  InnerException: