I too have tried all the different walkthroughs, all of them showing a different code, i've tried the ones you've suggested and i've played around for hours putting different combos, all in vain.
I'm at that stage where i'm thinking there must be something wrong with my copy of the game.
Could you clarify whether you leave the original code in an put the second one in after it, or delete the first one first? I've tried doing both.
Gah! I'm ripping hair from my head!
How are you supposed to guess a code that complex? Is there no where that points out the code?