Create a page as below and assign a limited toolset to each editor in the code behind:


 <telerik:RadEditor  ID="RadEditor1" Skin="Default"  ContentAreaMode="Div"   runat="server"      Width="265px" Height="120px"  ToolsWidth="265px">
       <Content><p>A Word</p> </Content>
</telerik:RadEditor>
        
 <telerik:RadEditor  ID="RadEditor2" Skin="Default"  ContentAreaMode="Div"   runat="server"     Width="265px" Height="120px"  ToolsWidth="265px">
       <Content><p>A Word</p> </Content>
</telerik:RadEditor>
        
[Continue with this until ...]

 <telerik:RadEditor  ID="RadEditor10" Skin="Default"  ContentAreaMode="Div"   runat="server"     Width="265px" Height="120px"  ToolsWidth="265px">
       <Content><p>A Word</p> </Content>
</telerik:RadEditor>
        
Now display this page and right click for the top editor's Context Sensitive popup menu. Now scroll down to the bottom menu and right click for that menu's context sensitive menu. My experience is that this will erroneously produce the popup at the top of the browser. This is the most extreme example of a general behaviour where the vertical placement of popups is typically off the mark when working with multiple editors and ContentAreaMode="Div". Get rid of the ContentAreaMode="Div" and the problem disappears.