@Conzume: This is an issue caused in some older games by the amount of RAM in newer computers. I had the same error with all maps in the game Vampire the Masquarade - Bloodlines.
This fix in that case was that I went in and changed my settings on RAM so that instead of running effectively with 4 GB RAM, it lowered it to only use 3 GB RAM. I don't know how much it would have to lower in order for D1 to work, or if this trick even works. The problem in VtM: BL, was that it read through the code too fast, thus getting to the end of some string which was never intended, because the older computers couldn't do so then. So lowering your RAM might help since it sounds like the same problem and if it doesn't work, you can always just turn it back to use full RAM again. Ofc. it's annoying having to change the RAM setting everytime you wanna play the game, but that was the only option with VtM: BL at least.