Multiplayer mode host
This trick requires two players in Multiplayer mode.
Have player one go to system link and create a game for Call Of Duty 2. Choose a level, set the times (30, 45, or 60 minutes) and other parameters. Remain at the screen and do not start the game.
Have player two start a different game, such as Perfect Dark Zero or an arcade game (so you do not have to change discs). Then, have player two invite player one to his game. Have player one accepts the invite, but when prompted to log out select “No”. You should now be the host of the game and it will be set to the way you want it.
Let me know if this works, or doesn’t work. I have heard that they might patch this at some point, but the recent patch should not have effected this.