From Fred Smith, "GraphicsWindowWin32::setWindow currently creates a context with no regards to the Traits, like createWindow does.

That is, it calls ::wglCreateContext to create a context, not the member method createContextImplementation(), which takes into an account the Traits.

In my situation, this prevents a GL 3.x context from being created.
"

src/osgViewer/GraphicsWindowWin32.cpp

@@ -1252,7 +1252,7 @@ bool GraphicsWindowWin32::setWindow( HWND handle )
         return false;
     }
 
-    _hglrc = ::wglCreateContext(_hdc);
+    _hglrc = createContextImplementation();
     if (_hglrc==0)
     {
         reportErrorForScreen("GraphicsWindowWin32::setWindow() - Unable to create OpenGL rendering context", _traits->screenNum, ::GetLastError());