I know the security code, but the door still won't open.

Hint 1 of 4:

The question is: HOW do you know the security code.

Hint 2 of 4:

At times, the game uses a bit of "intelligence" to thwart those who would
simply use a "walkthrough" to finish the game.

Hint 3 of 4:

You cannot "know" the code unless you have actually encountered Albert in the
Casino, and listened to the number he is betting.

Hint 4 of 4:

In other words, you can't "cheat".  If the code doesn't work, you didn't get
it from the game; you probably got it from this Hints file, or another source
outside of the game.