Hi Mike,

Thanks for the reply. Yeah you are right i have service which returns a list<ClassA> back.

Just to elaborate more over dynamic updates below is the piece of code

static void ServiceData_ListChanged(object sender, ListChangedEventArgs e)
        {
            if (e.ListChangedType == ListChangedType.ItemAdded)
            {
                SetRefreshButtonToolTip("Please click 'Update' to refresh the list");
                _workItem.CommandManager.RefreshFilterCommand.CanExecute = true; //enables a refresh button when user clicks on it the list updates. this is the recent update we did to avoid the error
            }
        }

//Responsible to update the control
        public void RefreshButton_Click()
        {
            _viewModel.OriginalDataList = _Service.GetReferenceData<ClassA>().ToList(); // gets the latest feeds and assign to the view model object
            ultraCombo1.DataSource = _viewModel.OriginalDataList; // assigning back to control
            SetRefreshButtonToolTip("Data is up to date");
        }

Can you please help me understanding whats going wrong here so i can try to correct and overcome. Else please suggest some solution or pointers to it. If threading is the only issue you see here ill make sure then im on UI thread when it re-assign data back to control.

Thanks,

Pratik