Your provided sample works just fine, and I probably did not give a good description of how my page is being built up. In the aspx I have a RadPanelBar. When I need to add the RadGrid to my page, it is added to the panelbar via code. So, my grid is inside a user control that is inside a panel, inside a panel bar.
Here is the code I use to add the panel. it is contained in a class call PanelBarFactory...
"Forms & Letters"
panelItem.ForeColor = Drawing.Color.Maroon
I add the user control into the panel with this ...
panelFormsLetters = panelFactory.GetFormsLettersPanels()
'this code is shown above
My workaround has been to eliminate the loading of the user control via code and just hide and show the control as needed.