Hi peterh, Solvegas,
I was playing around with my browser configuration (Firefox 42.0 on Windows 7). Maybe it is the same for you.
There is one thing you need to know, which is not a Beshine website problem.
A few months ago Firefox (and Chrome) deactivated Adobe Flash Player Add-On (also called Shock Wave in the Add-On section) by default. Because Flash Player is by far the biggest security hole in your whole PC .
Since Beshine's website is fully HTML 5 enabled your Firefox (and Chrome) can play Beshine movie streams without FlashPlayer (or FlashPlayer completely deactivated). But what needs to be enabled is Java Script. The player used (new since approx. 1-2 months) in that CMS of Beshine website is an open source player.
Then another thing is your internet speed. While certainly there is some level of compression enabled for the stream, still her movies have variable bitrate between 15-20 MB/s. If your internet speed isn't high enough, this could be a reason for streaming problems. Also old PC Hardware. My PC is soon 6 years old now. While I have no problem with my internet speed in general, my computer seems not able to decode fast enough the video stream transmitted via HTML 5 in the browser - it is jutting.
If you visit other models websites internet speed and speed of your PC might not be a problem, because they only have 1/12 - 1/6th of the bitrate of what Beshine has in her perfect quality videos.
So first thing is make sure you have the latest Firefox (and Chrome) version installed.
The good thing is the website built in movie player supports Flash as fall back. Therefore my solution for the moment until I want to buy a new PC (my previous PC was 10 years old until I replaced it ;-) computer manufacturer don't get rich by me) is, enable the Adobe Player Add-On again. Then it transmits, buffers and plays the movie again without jutting effects.
But before you do enalbe Flash Player again, make sure you have the latest version installed. Therefore you first need your internet browser updated, because Add-Ons are sometimes depending on browser versions.
Hope I could help.