Part 1 worked fine for me (except for the slowdown issue, but that's handled elsewhere), and I just DL'd Spinner Cay.
Game's great so far, BUT about half of the speech sound is completely missing. The characters move their mouths and the text is there, but I don't hear a thing. The other half of the time it's all there. A bit of testing showed that it's always the same soundfiles that work and don't work, but which files are affected seems random to me. For example, when you first meet Elaine, and she asks you to cooperate with LeChuck, all the "please" - "no" - "pretty please" etc. banter has no sound, but when Guybrush agrees, the sound is back again.
The shear randomness of missing/not missing is realli breaking the immersion for me. Any ideas?