I figured

I forgot to correct the PE Header for NT/2K.. Keep forgetting about that OS. Ok, it's fixed and runs on 2K now. Can you try it out before I re-up it to GCW? I've put it at this address temporarily:
members.xoom.com/LordCrass/D2-104US.zip
Let me know if it works for you.
The reason the file is so much smaller is because I removed the SecuROM code sections. Since the protection is no longer executed, it's simply been removed from the file. Amazing how much space it takes up, huh?