Yeah there's a bit of a difference in speed between region 1 (NTSC) and region 2 (PAL). Here's an article that can explain it better than I can. This is the most pertinent part of it though:
A less obvious effect of this 4% speedup is that the audio for the film is both 4% faster and 4% higher in pitch. In musical terms, this equates to a rise in pitch of a little under one semitone.