You are a life saver my friend

Had the same problem - Object reference not set to an instance of an object.
Failing at this line:
Code:this.Controls.Add( forumControl );
Funnily enough, session state wasn't set to true in my case but this is what I had:
<sessionState mode="Off" cookieless="false" timeout="20">
Anyways - commented it out, and my newly integrated forum is back and working

Thanks for posting your find anyways mate, saved me a great deal of head scratching!