Can’t play my videos in Skydrive anymore!

I recently created a folder with videos for one of my clients.  The videos are in MP4 and I used the same codec in all of them.  Everithing was OK until two days ago, when he called me complaining that he can't play some of the videos.  To my amazement, the player for some of the videos disappeared and the only way to play them is by downloading them to the computer.  To rule out some codec problem, I tried re-encoding some of them to Windows Media with the same results.  And now in every video I upload, I have the same problem again and again.  What's happening with them?  Is there a problem with Skydrive going on?