@Kris:I get this problem on my ipad with ALL high quality MP4 videos from channel9. I never worked out why so I tend to either download the HQ wmv and convert using format factory using ipad profile (also handy to crop at same time and get rid of presenter pic-in-pic so you can blow up the slides/demos) or download the wmv and play on ipad directly using AV Player HD which will play just about any format. However, it struggles with some hq wmv's whereby the audio goes out of sync (this is on an ipad 1, ipad 2 might be good, would love to know), at which point, i'll try the lower quality wmv or convert as mentioned above.