ASPX editing is not coupled to HTML designer. Name *.designer.cs file name somewhat misleading, it actually means "design-time generated code" it really has nothing to do with Design view. Now, if switching to and from Design view helps, perhaps IDE is not getting idle time, some hints here: http://blogs.msdn.com/mikhailarkhipov/archive/2008/04/02/wireless-mouse-html-editor-and-idle-time-processing.aspx