Do you have any ActiveX control or any user contorl on the Form ? If so this[^]and this[^]may help Be careful, there is no Undo Button(Ctrl+Z) in life.

I once encountered similar problem. I deleted the solution's user option file. It's usually located it the same directory as your solution file. It's hidden by default and has the same name as your solution file, but with ".suo" extension. I'm using VS2005. Excuse me for buttin' in, but I'm interrupt driven.