To register the v. 3.1 or v. 2.2 of the game do the following:

1) Set the date on your Mac to 1 Oct 2004
2) Enter Name: Santa Claus and Code: S871-5000-1800-0804-U267
3) Register
4) You can now restore the date on your Mac

The above procedure works in Mac OS X. To register v. 2.2 in Mac OS change the date year to 2003 (2004 may also work but I cannot test it as I first registered with the 2003 date)