The control with ID 'ScriptManagerProxy1' requires a
ScriptManager on the page. The ScriptManager must appear before any
controls that need it.
That error reads to me as though the proxy control can't find the RadScriptManager in the master page, or doesn't recognize it as a replacement for the standard ASP ScriptManager.
Could anyone clarify, is this configuration I am trying to use actually supported? If so, where exactly in the markup of the two pages should the RadScriptManager and ScriptManagerProxy declarations go? Or do they need to be added programatically for this to work? If someone could point me to a working example, that would be great - the RadControls documentation just says, 'Yes it works', but I can't find an example anywhere.