AJAX :: Control Toolkit Causes WCF Error / $inetinfo Is Undefined

I am using both the AJAX Control Toolkit HTMLEditor and making AJAX WCF calls from my web form. Since we can only have one Script Manager per page, I am using this:

<ajaxTools:ToolkitScriptManager
ID="ToolkitScriptManager1"
runat="server"><services><asp:servicereference
Path="AjaxServiceCall.svc"/></services></ajaxTools:ToolkitScriptManager>

When my page loads, I do an initial AJAX WCF call and it works.

But if I try to make an AJAX WCF call after the page has finished loading, I get the following error:

$inetinfo is undefined

If I take out the AJAX Control Toolkit script manager and replace it with this:

<asp:ScriptManager
ID="ScriptManager1"
runat="server"><services><asp:servicereference
Path="AjaxServiceCall.svc"
/></services></asp:ScriptManager>

Then my WCF AJAX works fine, but my HTMLEditor does not.