Commented Issue: Ajax Toolkit 4 does not work with ReportViewer 10 [26725]

After upgrading a project to use .net 4 and the new download I get the following error message for a page that contains a ReportViewer control version 10:

Microsoft JScript runtime error: Sys.ArgumentNullException: Value cannot be null.
Parameter name: panelsCreated[2]

I have tried changing the ScriptManager in the MasterPage to ToolkitScriptManager, but I keep getting the same error.
Comments: Set ScriptMode="Release" did not work for me. Any Solution please