ASP.NET,AJAX, SPGridView

[wagswvu]

I am trying to enclose SPGridView inside an UpdatePanel control in a user control page (.ascx), however whenever I click on the paging links for the grid, it still postbacks instead of partial page rendering. Also, this is not the first time I have used ajax in my project. I have taken the same code that has worked on other controls and applied them to the SPGridvew with no success. Below is a sample of the user control page in question with my override childcontrols. Any thoughts?

protected override void CreateChildControls()
        {
            // Register the AJAX ScriptManager
            ScriptManager ajaxScriptManager = ScriptManager.GetCurrent(this.Page);
 
            if (ajaxScriptManager == null)
            {
                ajaxScriptManager = new ScriptManager();
                ajaxScriptManager.ID = "AJAXScriptManager";
                ajaxScriptManager.EnablePartialRendering = true;
                this.Controls.Add(ajaxScriptManager);
            }
 
            EnsureAJAXUpdatePanelCompatibility();
 
            ajaxUpdatePanel = new UpdatePanel();
            ajaxUpdatePanel.ID = "AJAXUpdatePanel";
            ajaxUpdatePanel.ChildrenAsTriggers = true;
            ajaxUpdatePanel.UpdateMode = UpdatePanelUpdateMode.Conditional;
            this.Controls.Add(ajaxUpdatePanel);
 
            currentSite = SPContext.Current.Web;
 
            using (ListCaml listCaml = new ListCaml(currentSite))
            {
                searchID = ((SearchLibraryResultsPage)this.Page).searchID;                
                searchResultInfo = SearchProcessController.GetSearchResultInfo(searchID);
 
                using (Fields fields = new Fields())
                {
                    searchResultsInfoArray = fields.CreateStringValueArray(searchResultInfo);
                }
 
                elapsedTime = Convert.ToDouble(searchResultsInfoArray[0]);
                setNumber = Convert.ToInt16(searchResultsInfoArray[1]);
                rowStart = Convert.ToInt16(searchResultsInfoArray[2]);
                rowCount = Convert.ToInt16(searchResultsInfoArray[3]);
                isNextSet = Convert.ToBoolean(searchResultsInfoArray[4]);
                sortManagedProperty = searchResultsInfoArray[5];
                sortDirection = searchResultsInfoArray[6];
 
                searchResultsDT = (DataTable)Cache["SearchResults_" + searchID.ToString()];
                searchCriteriaDT = (DataTable)Cache["SearchCriteria_" + searchID.ToString()];               
 
                gridView = new SPGridView();
                searchResultsDV = new DataView(searchResultsDT);
                gridView.DataSource = searchResultsDV;             
 
                //CreateViewColumnMenu();
 
                searchCriteria = new StringBuilder();
 
                foreach (DataRow libraryFieldsDR in searchCriteriaDT.Rows)
                {
                    if (libraryFieldsDR["Value"].ToString() != string.Empty)
                    {
                        CreateSearchCriteriaList(libraryFieldsDR["Column_Name"].ToString(), libraryFieldsDR["Literal_Operator"].ToString(),
                                                 libraryFieldsDR["Data_Type"].ToString(),libraryFieldsDR["Value"].ToString());                       
                    }
 
                    if (libraryFieldsDR["Column_Name"].ToString() != "Path")
                    {
                        SPBoundField boundField = new SPBoundField();
                        boundField.HeaderText = libraryFieldsDR["Column_Name"].ToString();
                        boundField.DataField = libraryFieldsDR["Managed_Property"].ToString();                    
                        boundField.SortExpression = libraryFieldsDR["Managed_Property"].ToString();
                        gridView.Columns.Add(boundField);
                    }
                }
                gridView.AutoGenerateColumns = false;
                gridView.AllowSorting = true;
                gridView.AllowPaging = true;
                gridView.PagerSettings.Position = PagerPosition.Top;
                gridView.PagerSettings.Mode = PagerButtons.NumericFirstLast;
                gridView.PagerSettings.PageButtonCount = 5;               
                gridView.PageSize = listCaml.GetSearchResultLimits(Convert.ToInt16(Session["Current_LibraryID"]), SharePointSearch.resultsPerPage);
                gridView.Sorting += new GridViewSortEventHandler(gridView_Sorting);
                gridView.PageIndexChanging += new GridViewPageEventHandler(gridView_PageIndexChanging);
 
 
                ajaxUpdatePanel.ContentTemplateContainer.Controls.Add(gridView);
                //PagerTemplate must be added after you added the control, but before you bind your data
                gridView.PagerTemplate = null;
                gridView.DataBind();
 
                //AddResultsInformation();
 
                //Preserves the sorting when page is reload
                if ((!Page.IsPostBack) && (sortManagedProperty != string.Empty) && (sortDirection != string.Empty))
                {
                    ViewState["SortExpression"] = sortManagedProperty;
                    ViewState["SortDirection"] = sortDirection;
                    AddSortColumnArrows(gridView.HeaderRow,sortManagedProperty, sortDirection);
                    gridView.DataBind();
                }
            }
        }
 

[wagswvu]

Well after many of hours messing with this, I decided to just double check that the UpdatePanel was even working. So I added a TextBox and a Button with an EventHandler that would clear the text out of the TextBox. To my amazement, when I added those two controls the SPGridView started working... I did a few more experiments and soon I discovered that by just having a TextBox control visible on the screen would allow the SPGridView to work with the UpdatePanel. Take it off the page and SPGridView is back to full postbacks. I am now completely mystified on what’s going on, anybody have an idea?