You may face that altough:
You still can't change the layout. This seems a bug, as the layout button is enable by the querystring EditMode. So try to add ControlMode=Edit parameter in the querystring, and page layout should be enabled if the prerequisites are met.
note: When this blog post shows in the MSDN RSS feeds there is no indication as to what the topic is. VS? Sharepoint? ReportViewer? Hard to tell.
Will be very helpful if Sharepoint MSDN articles are prefixed with "Sharepoint". Just saying ;-)
Thank you thank you thank you
SAVED MY LIFE :D
but how to enable it by default as it's only a suitable solution for devs not for the client ?