Anyone who doesn't own Call of Duty 2 on Xbox 360 (and that's assuming you own an Xbox 360), buy it. It's great. If you do own it, then beware an evil, tiny bug that can screw up your saved game data and force you to execute a tactical withdrawal back to the start of the game.
Happily, though, Activision's well aware of the little blighter and has offered a couple of workarounds while it digs out its fly swatter and hunts the bug down. According to IGN, the bug usually crops up post-British campaign tank level, but a way to potentially dodge it and save your saved game data from doom is to log in to your player profile before heading into the action.
Apparently this isn't a completely foolproof method of bug evasion however, and to this end Activision has additionally released an unlock code that provides access to all single-player levels, which we guess is better than a poke in the navel from a bayonet.
In order to execute the cheat code you need to do the following (disclaimer: we've not actually tried this ourselves yet so don't blame us if it doesn't work): first, open the mission selection screen in the game; then hold down left and right shoulder buttons; keep them held down and then on the d-pad press left, left, right, right and then press button Y twice.
Activision says that if the saved game problem "is persistent or reoccurring you may need to enter this code more than once," so it's not a complete - or particularly ideal - solution. The publisher does mention that it's working directly with Microsoft to sort this bug out but no info on a release date for a fix has been given.