If I understand you, you don't see any of the on-screen info from your receiver on your monitor, right?
Are you sure that your monitor is getting its video feed through the receiver?
My 2400 has the ability to adjust the amount of info on the screen. I forget if one of the choices is no OSD at all. But if so, have you turned off the OSD function on the receiver accidentally? This feature is controlled via the remote on my 2400 but I think yours may be different.