Another video streaming problem

One streaming problem with my new HiX 10 which I discussed on this Forum has been solved by stopping Hardware Acceleration. Now I must solve a second problem which is that most videos are unable to play at all. Sometimes I get nothing as the video is unable to start, but if it does it stops quickly, with at best a second or so displayed. It seems to me that it is constantly buffering without ever being able to play. I get neither vision or sound.

I have a new Broadband service from which I receive around 40 Mbps. I use either WiFi or Ethernet cable, with the same results, Troubleshooters have revealed nothing (do they ever?). RAM is OK. I try both HD and SD and a variety of speeds. What can I try next?