I was having the same problem! I discovered that the game Full Throttle has at least 3 different versions. It seems that the lip sync only works correctly with ScummVM for some specific versions. The solution is arrange another version of the game different from the version you have. I did it and th...

I'm having the same problem!

I'm using the scummvm version 1.0.0rc143718 and the lipsync is completely out of time!