Created Unassigned: AjaxToolkit not work in IE8 [27910]

Hi, AjaxToolkit not work on IE8.

I have a page that have registered dll:
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>

This page inherit from master page that have an ScriptManager in it:
<asp:ScriptManager ID="asmGeneral" runat="server" AsyncPostBackTimeout="600" EnableScriptGlobalization="True"
EnableScriptLocalization="True"
OnAsyncPostBackError="asmGeneral_AsyncPostBackError" EnablePartialRendering="true">
<CompositeScript>
<Scripts>
<asp:ScriptReference Path="~/inc/js/jquery/jquery-1.11.1.min.js" />
<asp:ScriptReference Path="~/inc/js/general.js" />
</Scripts>
</CompositeScript>
</asp:ScriptManager>


I have in a page child of master the next code just to test the Toolkit and is painting the textBox as is it:
<asp:TextBox ID="Slider1" runat="server"></asp:TextBox>
<cc1:SliderExtender ID="SliderExtender1" runat="server"
TargetControlID="Slider1"
Minimum="-100"
Maximum="100"
Steps="5" />

This work fine in all browsers above IE8, but in IE8 not . If can help, i have in master the next meta-tag:
<meta http-equiv="X-UA-Compatible" content="IE=7, IE=9" />