ofSetupOpenGL error

When I use ofSetupOpenGL(640,480, OF_WINDOW); in ofMain.h,
when in my running app I move the mouse outside the window and again inside,
the mouse cursor doesn’t show anymore.

The error happens also when I use
#include “ofAppGLFWWindow.h”
ofAppGLFWWindow window;

With ofAppGlutWindow window; there is no error.

I use Mac OS X 10.6.8 with XCode 3.2.6

Isn’t this related ?