1.  create a rad grid with clientside binding and a clientdeletecolumn.  clientdelete column is buttontype=linkbutton and the linkbutton has a class for a background image
2.  set allowpaging="false" but don't set a page size
3.  populate grid so that it has 10 records
4.  all client delete buttons are visible
5.  add more records so that there are > 10 records
6.  records from 11>n will not show the clientdeletecolumn
7.  now, up the page size to something greater than your record count
8.  problem fixed

on viewing source you can see that the rgNoRecords tr is inserted after record 10 (default page size), which seems to affect the rendering below. the actual links for the client side delete columns are not rendered

Vertical Column Headers using rgRotateHeader seem to be a different, less readable, font than the regular horizontal column headers.  Please see attachment.  All those column headers are set to the same font.  To my eye, the rotated headers look quite poor.

I am using the following grid:
   <telerik:RadGrid style="overflow: hidden" CssClass="dm-Grid" ID="gridView" runat="server" AllowPaging="false" PageSize="25" Skin="TylerSilver" EnableEmbeddedSkins="false" EnableViewState="true"
            ExportSettings-ExportOnlyData="true" ExportSettings-IgnorePaging="true" AutoGenerateColumns="false" SortingSettings-SortedBackColor="#F0F0F0" EnableAlternatingRowColor="true"
            EnableAjaxSkinRendering="true" AllowSorting="true" ShowGroupPanel="false" GroupPanel-Enabled="false"
            ClientIdMode="AutoId" AllowFilteringByColumn="true" onneeddatasource="gridView_NeedDataSource" Onitemcreated="gridView_ItemCreated" onitemdatabound="gridView_ItemDataBound">
            <clientsettings>
        <clientevents onrowselected="RowSelected" onrowdeselected="RowSelected" oncolumnclick="OnColumnClick" OnColumnSwapped="ColumnSwapped" OnGridCreated="OnGridCreated"/>
    </clientsettings>
        </telerik:RadGrid>

Columns are dynamic, created in code-behind to match configurable datasets, via gridView.Columns.Add.  Each column has UniqueName, SortExpression, and HeaderText properties set - first two to the field name, last to plain-English version of the field name with spaces, etc.  Data binding is via a data table created from search results:

 gridView.DataSource = allDocumentsTable;

and using the following JS to activate the header cell context menus:

 function ShowColumnHeaderMenu(ev, index) {
            var grid = $find("<%=gridView.ClientID %>");
            var columns = grid.get_masterTableView().get_columns();
            columns[index - 1].showHeaderMenu(ev, 5, 5);
        }

I'm able to group columns using the menu but the "ungroup" command in the menu does not work.  If I turn on the grouping panel as a test (we do not want this UI style in production code), I can ungroup columns using the panel, but that does not change the behavour of the ungroup command in the header menu; it still does not work.

I've tried this with the Q2 2014 release and the problem is reproducible in that version.

Having a RadGrid in batch mode with Master and Details tables, when you add a new master record, you are not able to add a new detail record until you save the master record. 
This feature should be built in the RadGrid.

You can use the following temporary workaround in order to avoid the problem:
1. Attach OnGridCreated event handler:
    ...
    <ClientSettings>
         <ClientEvents OnGridCreated="onGridCreated" />
    </ClientSettings>
    ...

2. In the event handler configure the group header according to the number of visible columns in the grid:
          function onGridCreated(sender, args) {
              if ($telerik.isIE7) {
                  var visibleCount = sender.get_masterTableView()._getVisibleColumnsCount();
                  $telerik.$(".rgGroupHeader .rgGroupCol + td", sender.get_element()).attr("colspan", visibleCount);
              }
          }

We are using version 2012.Q3 of Telerik, for the RadGrid control.

Once we updated to VS 2013 Update 2, we experienced a rendering problem on our development machines for all RadGrids on our site.

Upon further review we found out that this was due to the Browser Link feature in VS 2013. Browser Link appears to inject code between the development environment and the web server(s).

We were able to fix this upon finding an article pointing us towards the Browser Link feature. However it did take quite a while to figure out the issue, so we wanted to pass this along so that you could create a Knowledge Base article about this so that others can find the solution more easily and quickly.

Resolution:
Add the following item to the AppSettings section of the Web.config
<add key="vs:EnableBrowserLink" value="false" />

References:
http://weblogs.asp.net/imranbaloch/archive/2013/10/23/messy-html-and-js-errors-when-you-install-visual-studio-2013.aspx

http://stackoverflow.com/questions/19513631/radgrid-rendering-differently-in-different-machine-of-100-same-application-when

http://www.asp.net/visual-studio/overview/2013/using-browser-link 
(what is Browser Link)

RadGrid cannot edit in IE8 under 2014Q2
javascript thows errors:
URI: http://localhost/Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=RadScriptManager1_TSM&compress=1&_TSM_CombinedScripts_=%3b%3bSystem.Web.Extensions%2c+Version%3d4.0.0.0%2c+Culture%3dneutral%2c+PublicKeyToken%3d31bf3856ad364e35%3azh-CN%3a8f393b2b-3315....

To fix the upper problem, we appyied 2014Q2SP1, however, in IE8, javascript thows new errors:
“sys is undefined” 
and the RadGrid does not display in web. But this is ok in debuging mode.

I want column width state maintain on postback. here with i am attaching may aspx page