My set up includes a Western Digital Mybook Nas which I store video in both divx and Mp4 formats. When playing back thru the hummy divx is fine but mp4 has a lip sync problem. I also have a sony blu ray player on the network which is dlna as well and it plays both file types ok. I'd preffer to use the hummy as it is able to FF/Rew mp4 whereas the sony wont. Any one any ideas?