Hi Viktor,
Well, I managed to get the code working in the sample app you provided but when I copy the code over to the real page I am running into an exception that says: "The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>)."
I am actually running this control on a nested master page. I put the Jacascript code in one of the body content placeholders (actually the only one). Some quick searches seem to indicate that the RadScriptBlock may need to be moved to a HEAD content placeholder. I haven't found eactly how to do that on a nested master page (the top level master exposes the HEAD tag, but not the second level one).
I just wanted to make sure that I am barking up the right tree here. Is there some other method I should be trying?