This is unrelated case to one we discuss in support ticket.
I tried to implement Sys.Application.Load approach, but having "sys is undefined" message. I tried to make it available, but had some config issues.
Also, i tried to set up opacity from code behind as radmap1.LayersCollection.Item(3).Opacity=0. Which was hiding layer ok but i could not to reset opacity back from client map.layers.options.opacity = 0.9
Any other recommendations?