Video glitch with h264 codec
When using addons such as "Enhancer for Youtube" (with the h264 option on) or "h264ify", after watching videos for a while, they start loading with a visual glitch that fixes itself after some seconds. It looks like if the image was blackwashed. It doesn't happen if I disable those addons, but videos don't look as good without them.
Any ideas of why it happens?