Almost every game that has speech has problems. Speech is so compressed and complicated that it is hard to get it just right. However, this is a known problem and I would that that, eventually, if possible, it will be fixed.
Well, thanks anyway. The internal SPU does do the voice, but it hangs on certain parts until the 'skip' key is pressed (for Misadventures it's start). The location appears to be at the point right after the specific voice sample is played, but it has happened in the middle of a person's speech.