Hi, I'm working my way through the surfing with the alien volume two tutorials. I've reached part 11 and have discovered a video lag that gets worse the further into the video I go. I only noticed it about half way through the tut but it has now gotten to the point where it's eleven seconds out (for example: the tutor says 'so lets rearrange the graph' and the video shows this happening eleven seconds later when he's gone onto a different part.)

If this could be looked into and fixed I'd be very grateful.

Thanks, the Yeti.