.NET - CheckBrowserCompatibility() problem

Hi,
I've been trying to integrate FCKeditor with a .NET CMS I've been working on. I have the following:

=======================

Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter)
If (isEditable) Then
Dim editor As New FCKeditor
editor.BasePath = "/edit/"
editor.Value = content
editor.EditorAreaCSS = "css/default.css"

editor.RenderControl(output)

=======================

in an instance of System.Web.UI.WebControls.WebControl. When I try to run my app, however, I get a NullReferenceException in the FredCK.FCKeditorV2.FCKeditor.CheckBrowserCompatibility() function. Has anyone else had this problem? The complete stack trace is:

=======================

[NullReferenceException: Object reference not set to an instance of an object.]
FredCK.FCKeditorV2.FCKeditor.CheckBrowserCompatibility() +13
FredCK.FCKeditorV2.FCKeditor.Render(HtmlTextWriter writer) +31
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +243
AstraZeneca.Wasp.Articles.HtmlPage.Render(HtmlTextWriter output) in c:\inetpub\wwwroot\WASP.NET\Articles\htmlPage.vb:42
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +243
AstraZeneca.Wasp.WaspCoreHandler.ProcessRequest(HttpContext context) in c:\inetpub\wwwroot\WASP.NET\WaspCoreHandler.vb:40
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute() +179
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +87

=======================

I'd appreciate any help, but if I find a fix I'll post it here. Thanks in advance,

Sam