Stayce: I've just bought this game, running windows 8.1 64bit and don't seem to have had too many issues with it. The first time I loaded it I set the resolution to my monitor (1920x1080) running as an admin. The game loaded but as has been reported the frame rate was awful.
I went back into the graphics settings and lowered the resolution dramatically to 800x600 and changed the renderer to one of the direct x 7 ones. Booted up the game and the frame rate is now pretty smooth for the most part although I haven't played much so I have no idea how it will hold up as the game goes on.
The loss in fidelity really doesn't affect the game much. It was never a looker and to be honest I could see very little difference between the two with exception of a noticeably larger interface and cursor, strange as it may sound.
Don't know if this will be the same for everyone however.
i can attest that your fix does smooth the game out a fair bit but it is still choppy, although i am running windows 8 not 8.1 so i will edit after upgrading