if anyone’s still having the swamp lock-up problem, you could try to start the game using DOSBox, then put set the game to Text, lower the volume and detail to 0 (keep the game in windowed mode, not fullscreen) and get through that scene, then save and play the game as you usually would from that restore point.
It worked like a charm for me :), if it doesn’t work, try messing with the CPU cycle settings (ctrl-F11 decreases and ctrl-F12 increases) or the Frameskip settings (ctrl-F8 increases and ctrl-F7 decreases) 🙂