No solution yet. For now I have to use RadAjaxPanel.
Im hoping it will be fixed in the next release.
I have a question: have you had any trouble using the RadScriptManager?
When I put that on my master page, some of the content pages give an error.
Cant remember what it was now but the page wont load at all.
As a result Ive had to use the standard Ajax ScriptManager and as a result I cant benefit
from script combining and compression.