I cant tell you how many times i have invested four or five hours to make it to wave 50, 60 and beyond just to have the game lag out after only 3 seconds! Especially when its not our connection and its mw3's servers that went down. I seriously would not mine waiting 5 to 10 minutes for the server to reboot and reconnect.  But to work  that hard on a map for a three second lag out ending the game is ridiculous! Fix this please