When i put in my MW2 disc it reads fine. 100%. I go to multiplayer and it loads up but i attempt to get in a lobby and the whole xbox jams so i need to restart the xbox. Or another thing that happens is I get into a lobby and sometimes it will work. But sometimes i get major lag and then my whole xbox jams meaning i need to restart my xbox. And it can happen 4-5 times in a row and by then i am off my head so i turn it off and leave it. The thing is tho it works perfectly fine offline. As soon as i go onto live it jams. This only has happened since i got the new xbox 360 250gb/slim. My arcade worked fine.