I got an e-mail from a random guy on the internet that said he wished it worked on Windows 7 64-bit. I'd had major issues with getting it to work in spite of UAC (writing to Program Files is a no-no) and targeting a multi-architecture CPU. I'm a little smarter now and got it working tonight.
Other than the bug fix (to work on 64-bit), the only other change was saving the data file to your roaming profile (C:\Users\USERNAME\AppData\Roaming\Mafia\Mafia.sdf) instead of to the program files folder.
Enjoy - if you still use it or wanted to. -- flickr | 'Cause I've been waiting, all my life just waiting For you to shine, shine your light on me