I put in my save code in the darkroom and played the game. The code I got got after the game does not work.

Chrash_Plague, that's just 100% spam.

Did you put the savegame code at dark room, and got the other code to the locker in the bar at first floor(second for map) by doing the "mission"? And then you directly put the code at the locker? Then that should work!

What I think you did wrong:

The internet code changes everytime you save the game, and so does the correct locker code.
So if you saved/overwrote the current game/internet-code before entered the code, the code will be unuseable.

What to do if you still didn't get it(doing exactly this should do the job):

Save your BG&E game, and remember the code (write it down or something).
Log in at ubi, and go to: http://darkroom.ubi.com/mission_end.php?mission_success=1 --- This is a great, but kinda unuseable cheat.
Load the gamesave, and goto the locker and enter the code.