Really? I admit I don't normally use the Emacs bindings in Visual Studio myself, but I just tried them and ctrl-x ctrl-s saves the file just fine for me. (This is using Visual Studio 2005, under the Tools | Customize menu option, Keyboard... button, Emacs keyboard mapping scheme.)
No no, I mean that I don't use the Emacs bindings because other things don't work the way I want, like tabbing. So when I'm using the c# bindings I find myself running strange commands accidentally.