Hi rdocter, First please check to make sure your drivers are up to date: Upgrade your graphics drivers to use hardware acceleration and WebGL

In order to better assist you with your issue please provide us with a screenshot. If you need help to create a screenshot, please see How do I create a screenshot of my problem?

Once you've done this, attach the saved screenshot file to your forum post by clicking the Browse... button below the Post your reply box. This will help us to visualize the problem.

Also please provide a link where this might be happening.

Thank you!

Is this problem with any other site? Is it a few clips, many, all?

Download the clip and use a player. Is the problem still there?

Thanks for the reply. My software is up to date. Then I tried to turn off the hardware acceleration, with no noticeable effect. Then I looked at webgl, which was disabled - reset it to true and restarted Firefox; again no effect.

The screen shot is from Amazon prime video, http://www.amazon.com/gp/product/B00QJ4DSMS/ref=dv_dp_ep3

Its a pay site, so I can't check it myself.

Have you tried downloading the clip?

Use a web search, and see if it shows up somewhere else.