This is ridiculous and unfortunate. Why should something like streaming internet video be tied to something like that, when the hardware is capable? Maybe because Netflix uses Silverlight and Silverlight is also Microsoft. :-\
If your device is plugged into a power strip, try plugging it directly into a wall socket even if you have to use an extension cord. My issues with silverlight resolved when I did this. I replaced the power strip with a Belkin product and haven't had a problem since.
For what it's worth, this was an ongoing issue for my Windows XP media machine until I did a clean install of the Windows 10 Insider Preview. For whatever reason, the tearing issue is now completely gone. Better Windows internals? Or perhaps just doing a clean install did the trick. I may never know for sure. Intel G43/G45, 32-bit Windows, Firefox.