I'm having issues with MW3 at the moment which render it unplayable for me. For some reason, whenever I try posting the details here it tells me the content isn't allowed and won't let me, so everything you need to know is here:
Try clicking the "select" button so it would only search for the original maps. If that doesn't work, then you have to download the newest maps that are available to you. And yes it happens to everyone until you don't the maps.