I'm getting a different styling on checkboxes with 2013.3 SP1. Take a look at the attached screenshots, one from version 2013.3.1015 and the other from 2013.3.1114. These are both IE 8, Windows XP Pro. Firefox does not have this difference. In FF, the 1114 version looks the same as the 1015 version Here is a boiled down version of the ASPX page with RadGrid, single column, checkbox in header.
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="TestCheckbox.aspx.cs" Inherits="TestCheckbox" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<
html
xmlns
=
"http://www.w3.org/1999/xhtml"
>
<
head
runat
=
"server"
>
<
title
></
title
>
</
head
>
<
body
>
<
form
id
=
"form1"
runat
=
"server"
>
<
telerik:RadScriptManager
ID
=
"RadScriptManager1"
runat
=
"server"
>
<
Services
>
<
asp:ServiceReference
path
=
"~/WS/wsIHExplorer.asmx"
/>
</
Services
>
</
telerik:RadScriptManager
>
<
telerik:RadSkinManager
ID
=
"RadSkinManager1"
runat
=
"server"
Skin
=
"Default"
ShowChooser
=
"false"
/>
<
telerik:RadAjaxLoadingPanel
runat
=
"server"
ID
=
"RadAjaxLoadingPanel1"
/>
<
telerik:RadGrid
ID
=
"RadGrid1"
runat
=
"server"
AutoGenerateColumns
=
"false"
Width
=
"100%"
Height
=
"100%"
BorderWidth
=
"0px"
AllowMultiRowSelection
=
"true"
>
<
PagerStyle
Mode
=
"NextPrevAndNumeric"
AlwaysVisible
=
"true"
/>
<
MasterTableView
TableLayout
=
"Fixed"
AutoGenerateColumns
=
"false"
PageSize
=
"10"
AllowPaging
=
"true"
AllowSorting
=
"true"
AllowNaturalSort
=
"false"
>
<
Columns
>
<
telerik:GridTemplateColumn
UniqueName
=
"Selection"
HeaderStyle-Width
=
"60px"
HeaderStyle-HorizontalAlign
=
"Center"
>
<
HeaderTemplate
>
<
asp:CheckBox
ID
=
"chkSelectionHeader"
runat
=
"server"
/>
</
HeaderTemplate
>
<
ClientItemTemplate
>
<
table
cellspacing
=
"0"
cellpadding
=
"0"
width
=
"100%"
>
<
tr
>
<
td
align
=
"center"
><
input
id
=
"chkSelection"
type
=
"checkbox"
/></
td
>
</
tr
>
</
table
>
</
ClientItemTemplate
>
<
ItemStyle
HorizontalAlign
=
"Center"
/>
</
telerik:GridTemplateColumn
>
</
Columns
>
<
NoRecordsTemplate
>
<
div
>
</
div
>
</
NoRecordsTemplate
>
</
MasterTableView
>
<
ClientSettings
>
<
ClientEvents
OnCommand
=
"function () {}"
/>
<
Selecting
AllowRowSelect
=
"true"
UseClientSelectColumnOnly
=
"true"
/>
<
Scrolling
AllowScroll
=
"true"
UseStaticHeaders
=
"true"
/>
<
DataBinding
ShowEmptyRowsOnLoad
=
"false"
/>
</
ClientSettings
>
</
telerik:RadGrid
>
</
form
>
</
body
>
</
html
>