Including font name and insert image in HTML Editor extender.

I want to add "Segoe UI" font in the HTML editor extender font family dropdown. So I have downloaded the latest source from codeplex http://ajaxcontroltoolkit.codeplex.com/SourceControl/latest#ReadMe.html and added the font in htmleditorextender.pre.js. Its working fine. Also I have to include the image uploader in the editor. 

<asp:TextBox runat="server" ID="txtBox2" TextMode="MultiLine" Columns="50" Rows="10"
Text="Hello <b>world!</b>" /><br />
<ajaxToolkit:HtmlEditorExtender ID="htmlEditorExtender2" TargetControlID="txtBox2"
runat="server" DisplaySourceTab="True" OnImageUploadComplete="ajaxFileUpload_OnUploadComplete">
<Toolbar>
<ajaxToolkit:Bold />
<ajaxToolkit:Italic />
<ajaxToolkit:Underline />
<ajaxToolkit:HorizontalSeparator />
<ajaxToolkit:JustifyLeft />
<ajaxToolkit:JustifyCenter />
<ajaxToolkit:JustifyRight />
<ajaxToolkit:JustifyFull />
<ajaxToolkit:CreateLink />
<ajaxToolkit:UnLink />
<ajaxToolkit:InsertImage />

</Toolbar>
</ajaxToolkit:HtmlEditorExtender>

while including the image uploader am getting the following error.

"Microsoft JScript runtime error: Unable to get value of the property 'Control': object is null or undefined" in the below line.

Sys.Application.add_init(function() {
$create(Sys.Extended.UI.AjaxFileUpload.Control, {"allowedFileTypes":"jpg,jpeg,gif,png","clientStateField":$get("SampleContent_htmlEditorExtender2_ajaxFileUpload_ClientState"),"contextKey":"{DA8BEDC8-B952-4d5d-8CC2-59FE922E2923}","postBackUrl":"/AjaxControlToolkitSampleSite/HtmlEditorExtender/HtmlEditorExtender.aspx","serverPollingSupport":true}, {"uploadComplete":ajaxClientUploadComplete}, null, $get("SampleContent_htmlEditorExtender2_ajaxFileUpload"));
});

Can anyone help me to resolve this one? I have already Changed CombineScripts="false" but not resolving the issue.

But if i remove the <ajaxToolkit:InsertImage />  editor is working fine.

<asp:TextBox runat="server" ID="txtBox2" TextMode="MultiLine" Columns="50" Rows="10"
Text="Hello <b>world!</b>" /><br />
<ajaxToolkit:HtmlEditorExtender ID="htmlEditorExtender2" TargetControlID="txtBox2"
runat="server" DisplaySourceTab="True" OnImageUploadComplete="ajaxFileUpload_OnUploadComplete">
<Toolbar> 
<ajaxToolkit:Bold />
<ajaxToolkit:Italic />
<ajaxToolkit:Underline />
<ajaxToolkit:HorizontalSeparator />
<ajaxToolkit:JustifyLeft />
<ajaxToolkit:JustifyCenter />
<ajaxToolkit:JustifyRight />
<ajaxToolkit:JustifyFull />
<ajaxToolkit:CreateLink />
<ajaxToolkit:UnLink />
</Toolbar>
</ajaxToolkit:HtmlEditorExtender>

Thanks,

Suresh.