FCKEditor not working in contentplaceholder : DOTNET

I'm having trouble getting FCKEditor to work in a contentplaceholder.
The code works fine on a single page, but fails in a master/details
configuration. Specifically, FCKEditor won't render when embedded in a
contentplaceholder. I tested it both on IE 7.0 and FF 2.0.0.11 with
ASP.NET 2.0 and 3.0 using FCKEditor version 2.5 and also .NET version
2.2.

FCKEditor actually requires a dll (FredCK.FCKeditorV2.dll) in the bin
directory. Are there any special registrations steps required when
binding an assembly control into a details page? All samples I looked
up are implemented on a single page. TIA for any hints.

Sample (works):
<%@ Page Language="VB" ValidateRequest="false"
AutoEventWireup="false" %>
<%@ Register TagPrefix="FCKeditorV2" Namespace="FredCK.FCKeditorV2"
Assembly="FredCK.FCKeditorV2" %>
....
<form id="form1" runat="server">
<FCKeditorV2:FCKeditor id="FCKeditor1" BasePath="~/FCKeditor/"
runat="server" />
<br />
<input id="Submit1" type="submit" value="Submit" runat="server" /
>
</form>

Sample (fails ie. FCKEditor not rendered):
<%@ Page Language="VB" MasterPageFile="~/Site.master"
ValidateRequest="false" AutoEventWireup="false" Title="Untitled Page"
%>
<%@ Register TagPrefix="FCKeditorV2" Namespace="FredCK.FCKeditorV2"
Assembly="FredCK.FCKeditorV2" %>

<asp:Content ID="Content2" ContentPlaceHolderID="CPM1" Runat="Server">
<FCKeditorV2:FCKeditor id="FCKeditor1" BasePath="~/FCKeditor/"
runat="server" />
<br />
<input id="Submit1" type="submit" value="Submit" runat="server" />
</asp:Content>